X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=remoteglot.pl;h=7f1a6687e72aa597827212a95a673b429e1b2bd2;hp=bb16ebcbd9931d23cc360dfac948b9faeed59c17;hb=7314c1611dbab18a6ebdd5934697dd5cf94ed437;hpb=a5d359eaff725889fd3554a7c3b7ac5088eb7c63

diff --git a/remoteglot.pl b/remoteglot.pl
index bb16ebc..7f1a668 100755
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -9,10 +9,18 @@
 # Licensed under the GNU General Public License, version 2.
 #
 
+use AnyEvent;
+use AnyEvent::Handle;
+use AnyEvent::HTTP;
+use Chess::PGN::Parse;
+use EV;
 use Net::Telnet;
 use FileHandle;
 use IPC::Open2;
 use Time::HiRes;
+use JSON::XS;
+require 'Position.pm';
+require 'Engine.pm';
 use strict;
 use warnings;
 
@@ -20,12 +28,9 @@ use warnings;
 my $server = "freechess.org";
 my $target = "GMCarlsen";
 my $engine_cmdline = "'./Deep Rybka 4 SSE42 x64'";
-my $engine2_cmdline = "./stockfish_13111119_x64_modern_sse42";
-my $telltarget = undef;   # undef to be silent
-my @tell_intervals = (5, 20, 60, 120, 240, 480, 960);  # after each move
+my $engine2_cmdline = "./stockfish_13111119_x64_modern_sse42";  # undef for none
 my $uci_assume_full_compliance = 0;                    # dangerous :-)
-my $update_max_interval = 2.0;
-my $second_engine_start_depth = 8;
+my $update_max_interval = 1.0;
 my @masters = (
 	'Sesse',
 	'Sessse',
@@ -35,8 +40,9 @@ my @masters = (
 );
 
 # Program starts here
-$SIG{ALRM} = sub { output_screen(); };
+$SIG{ALRM} = sub { output(); };
 my $latest_update = undef;
+my $http_timer = undef;
 
 $| = 1;
 
@@ -54,13 +60,11 @@ $| = 1;
 select(STDOUT);
 
 # open the chess engine
-my $engine = open_engine($engine_cmdline, 'E1');
-my $engine2 = open_engine($engine2_cmdline, 'E2');
-my ($last_move, $last_tell);
+my $engine = open_engine($engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
+my $engine2 = open_engine($engine2_cmdline, 'E2', sub { handle_uci(@_, 0); });
+my $last_move;
 my $last_text = '';
-my $last_told_text = '';
-my ($pos_waiting, $pos_calculating, $move_calculating_second_engine);
-my %refutation_moves = ();
+my ($pos_waiting, $pos_calculating, $pos_calculating_second_engine);
 
 uciprint($engine, "setoption name UCI_AnalyseMode value true");
 # uciprint($engine, "setoption name NalimovPath value /srv/tablebase");
@@ -69,13 +73,15 @@ uciprint($engine, "setoption name Hash value 1024");
 # uciprint($engine, "setoption name MultiPV value 2");
 uciprint($engine, "ucinewgame");
 
-uciprint($engine2, "setoption name UCI_AnalyseMode value true");
-# uciprint($engine2, "setoption name NalimovPath value /srv/tablebase");
-uciprint($engine2, "setoption name NalimovUsage value Rarely");
-uciprint($engine2, "setoption name Hash value 1024");
-uciprint($engine2, "setoption name Threads value 8");
-# uciprint($engine2, "setoption name MultiPV value 2");
-uciprint($engine2, "ucinewgame");
+if (defined($engine2)) {
+	uciprint($engine2, "setoption name UCI_AnalyseMode value true");
+	# uciprint($engine2, "setoption name NalimovPath value /srv/tablebase");
+	uciprint($engine2, "setoption name NalimovUsage value Rarely");
+	uciprint($engine2, "setoption name Hash value 1024");
+	uciprint($engine2, "setoption name Threads value 8");
+	uciprint($engine2, "setoption name MultiPV value 500");
+	uciprint($engine2, "ucinewgame");
+}
 
 print "Chess engine ready.\n";
 
@@ -92,128 +98,28 @@ $t->cmd("set shout 0");
 $t->cmd("set seek 0");
 $t->cmd("set style 12");
 $t->cmd("observe $target");
-
-# main loop
 print "FICS ready.\n";
-while (1) {
-	my $rin = '';
-	my $rout;
-	vec($rin, fileno($engine->{'read'}), 1) = 1;
-	vec($rin, fileno($engine2->{'read'}), 1) = 1;
-	vec($rin, fileno($t), 1) = 1;
-
-	my ($nfound, $timeleft) = select($rout=$rin, undef, undef, 5.0);
-	my $sleep = 1.0;
-
-	while (1) {
-		my $line = $t->getline(Timeout => 0, errmode => 'return');
-		last if (!defined($line));
-
-		chomp $line;
-		$line =~ tr/\r//d;
-		if ($line =~ /^<12> /) {
-			my $pos = style12_to_pos($line);
-			
-			# if this is already in the queue, ignore it
-			next if (defined($pos_waiting) && $pos->{'fen'} eq $pos_waiting->{'fen'});
-
-			# if we're already chewing on this and there's nothing else in the queue,
-			# also ignore it
-			next if (!defined($pos_waiting) && defined($pos_calculating) &&
-			         $pos->{'fen'} eq $pos_calculating->{'fen'});
-
-			# if we're already thinking on something, stop and wait for the engine
-			# to approve
-			if (defined($pos_calculating)) {
-				if (!defined($pos_waiting)) {
-					uciprint($engine, "stop");
-				}
-				if ($uci_assume_full_compliance) {
-					$pos_waiting = $pos;
-				} else {
-					uciprint($engine, "position fen " . $pos->{'fen'});
-					uciprint($engine, "go infinite");
-					$pos_calculating = $pos;
-				}
-			} else {
-				# it's wrong just to give the FEN (the move history is useful,
-				# and per the UCI spec, we should really have sent "ucinewgame"),
-				# but it's easier
-				uciprint($engine, "position fen " . $pos->{'fen'});
-				uciprint($engine, "go infinite");
-				$pos_calculating = $pos;
-			}
-
-			%refutation_moves = calculate_refutation_moves($pos);
-			if (defined($move_calculating_second_engine)) {
-				uciprint($engine2, "stop");
-				$move_calculating_second_engine = undef;
-			} else {
-				give_new_move_to_second_engine($pos);
-			}
 
-			$engine->{'info'} = {};
-			$engine2->{'info'} = {};
-			$last_move = time;
-
-			# 
-			# Output a command every move to note that we're
-			# still paying attention -- this is a good tradeoff,
-			# since if no move has happened in the last half
-			# hour, the analysis/relay has most likely stopped
-			# and we should stop hogging server resources.
-			#
-			$t->cmd("date");
-		}
-		if ($line =~ /^([A-Za-z]+)(?:\([A-Z]+\))* tells you: (.*)$/) {
-			my ($who, $msg) = ($1, $2);
-
-			next if (grep { $_ eq $who } (@masters) == 0);
-	
-			if ($msg =~ /^fics (.*?)$/) {
-				$t->cmd("tell $who Executing '$1' on FICS.");
-				$t->cmd($1);
-			} elsif ($msg =~ /^uci (.*?)$/) {
-				$t->cmd("tell $who Sending '$1' to the engine.");
-				print { $engine->{'write'} } "$1\n";
-			} else {
-				$t->cmd("tell $who Couldn't understand '$msg', sorry.");
-			}
-		}
-		#print "FICS: [$line]\n";
-		$sleep = 0;
-	}
-	
-	# any fun on the UCI channel?
-	if ($nfound > 0 && vec($rout, fileno($engine->{'read'}), 1) == 1) {
-		my @lines = read_lines($engine);
-		for my $line (@lines) {
-			next if $line =~ /(upper|lower)bound/;
-			handle_uci($engine, $line, 1);
-		}
-		$sleep = 0;
+my $ev1 = AnyEvent->io(
+	fh => fileno($t),
+	poll => 'r',
+	cb => sub {    # what callback to execute
+		while (1) {
+			my $line = $t->getline(Timeout => 0, errmode => 'return');
+			return if (!defined($line));
 
-		output_screen();
-	}
-	if ($nfound > 0 && vec($rout, fileno($engine2->{'read'}), 1) == 1) {
-		my @lines = read_lines($engine2);
-		for my $line (@lines) {
-			next if $line =~ /(upper|lower)bound/;
-			handle_uci($engine2, $line, 0);
+			chomp $line;
+			$line =~ tr/\r//d;
+			handle_fics($line);
 		}
-		$sleep = 0;
-
-		output_screen();
 	}
-
-	sleep $sleep;
-}
+);
+# Engine events have already been set up by Engine.pm.
+EV::run;
 
 sub handle_uci {
 	my ($engine, $line, $primary) = @_;
 
-	chomp $line;
-	$line =~ tr/\r//d;
 	$line =~ s/  / /g;  # Sometimes needed for Zappa Mexico
 	print UCILOG localtime() . " $engine->{'tag'} <= $line\n";
 	if ($line =~ /^info/) {
@@ -232,23 +138,136 @@ sub handle_uci {
 		if ($primary) {
 			return if (!$uci_assume_full_compliance);
 			if (defined($pos_waiting)) {
-				uciprint($engine, "position fen " . $pos_waiting->{'fen'});
+				uciprint($engine, "position fen " . $pos_waiting->fen());
 				uciprint($engine, "go infinite");
 
 				$pos_calculating = $pos_waiting;
 				$pos_waiting = undef;
 			}
 		} else {
-			if (defined($move_calculating_second_engine)) {	
-				my $move = $refutation_moves{$move_calculating_second_engine};
-				$move->{'pv'} = $engine->{'info'}{'pv'} // $engine->{'info'}{'pv1'};
-				$move->{'score_cp'} = $engine->{'info'}{'score_cp'} // $engine->{'info'}{'score_cp1'} // 0;
-				$move->{'score_mate'} = $engine->{'info'}{'score_mate'} // $engine->{'info'}{'score_mate1'};
-				$move->{'toplay'} = $pos_calculating->{'toplay'};
-			}
-			give_new_move_to_second_engine($pos_waiting // $pos_calculating);
+			$engine2->{'info'} = {};
+			my $pos = $pos_waiting // $pos_calculating;
+			uciprint($engine2, "position fen " . $pos->fen());
+			uciprint($engine2, "go infinite");
+			$pos_calculating_second_engine = $pos;
+		}
+	}
+	output();
+}
+
+sub handle_fics {
+	my $line = shift;
+	if ($line =~ /^<12> /) {
+		handle_position(Position->new($line));
+	}
+	if ($line =~ /^([A-Za-z]+)(?:\([A-Z]+\))* tells you: (.*)$/) {
+		my ($who, $msg) = ($1, $2);
+
+		next if (grep { $_ eq $who } (@masters) == 0);
+
+		if ($msg =~ /^fics (.*?)$/) {
+			$t->cmd("tell $who Executing '$1' on FICS.");
+			$t->cmd($1);
+		} elsif ($msg =~ /^uci (.*?)$/) {
+			$t->cmd("tell $who Sending '$1' to the engine.");
+			print { $engine->{'write'} } "$1\n";
+		} elsif ($msg =~ /^pgn (.*?)$/) {
+			my $url = $1;
+			$t->cmd("tell $who Starting to poll '$url'.");
+			AnyEvent::HTTP::http_get($url, sub {
+				handle_pgn(@_, $url);
+			});
+		} elsif ($msg =~ /^stoppgn$/) {
+			$t->cmd("tell $who Stopping poll.");
+			$http_timer = undef;
+		} elsif ($msg =~ /^quit$/) {
+			$t->cmd("tell $who Bye bye.");
+			exit;
+		} else {
+			$t->cmd("tell $who Couldn't understand '$msg', sorry.");
+		}
+	}
+	#print "FICS: [$line]\n";
+}
+
+sub handle_pgn {
+	my ($body, $header, $url) = @_;
+	my $pgn = Chess::PGN::Parse->new(undef, $body);
+	if (!defined($pgn) || !$pgn->read_game()) {
+		warn "Error in parsing PGN from $url\n";
+	} else {
+		$pgn->quick_parse_game;
+		my $pos = Position->start_pos($pgn->white, $pgn->black);
+		my $moves = $pgn->moves;
+		for my $move (@$moves) {
+			my ($from_row, $from_col, $to_row, $to_col, $promo) = $pos->parse_pretty_move($move);
+			$pos = $pos->make_move($from_row, $from_col, $to_row, $to_col, $promo);
+		}
+		handle_position($pos);
+	}
+	
+	$http_timer = AnyEvent->timer(after => 1.0, cb => sub {
+		AnyEvent::HTTP::http_get($url, sub {
+			handle_pgn(@_, $url);
+		});
+	});
+}
+
+sub handle_position {
+	my ($pos) = @_;
+		
+	# if this is already in the queue, ignore it
+	return if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen());
+
+	# if we're already chewing on this and there's nothing else in the queue,
+	# also ignore it
+	return if (!defined($pos_waiting) && defined($pos_calculating) &&
+		 $pos->fen() eq $pos_calculating->fen());
+
+	# if we're already thinking on something, stop and wait for the engine
+	# to approve
+	if (defined($pos_calculating)) {
+		if (!defined($pos_waiting)) {
+			uciprint($engine, "stop");
+		}
+		if ($uci_assume_full_compliance) {
+			$pos_waiting = $pos;
+		} else {
+			uciprint($engine, "position fen " . $pos->fen());
+			uciprint($engine, "go infinite");
+			$pos_calculating = $pos;
 		}
+	} else {
+		# it's wrong just to give the FEN (the move history is useful,
+		# and per the UCI spec, we should really have sent "ucinewgame"),
+		# but it's easier
+		uciprint($engine, "position fen " . $pos->fen());
+		uciprint($engine, "go infinite");
+		$pos_calculating = $pos;
 	}
+
+	if (defined($engine2)) {
+		if (defined($pos_calculating_second_engine)) {
+			uciprint($engine2, "stop");
+		} else {
+			uciprint($engine2, "position fen " . $pos->fen());
+			uciprint($engine2, "go infinite");
+			$pos_calculating_second_engine = $pos;
+		}
+		$engine2->{'info'} = {};
+	}
+
+	$engine->{'info'} = {};
+	$last_move = time;
+
+	# 
+	# Output a command every move to note that we're
+	# still paying attention -- this is a good tradeoff,
+	# since if no move has happened in the last half
+	# hour, the analysis/relay has most likely stopped
+	# and we should stop hogging server resources.
+	#
+	$t->cmd("date");
 }
 
 sub parse_infos {
@@ -257,19 +276,30 @@ sub parse_infos {
 
 	my $info = $engine->{'info'};
 
+	# Search for "multipv" first of all, since e.g. Stockfish doesn't put it first.
+	for my $i (0..$#x - 1) {
+		if ($x[$i] eq 'multipv') {
+			$mpv = $x[$i + 1];
+			next;
+		}
+	}
+
 	while (scalar @x > 0) {
-		if ($x[0] =~ 'multipv') {
+		if ($x[0] eq 'multipv') {
+			# Dealt with above
+			shift @x;
 			shift @x;
-			$mpv = shift @x;
 			next;
 		}
-		if ($x[0] =~ /^(currmove|currmovenumber|cpuload)$/) {
+		if ($x[0] eq 'currmove' || $x[0] eq 'currmovenumber' || $x[0] eq 'cpuload') {
 			my $key = shift @x;
 			my $value = shift @x;
 			$info->{$key} = $value;
 			next;
 		}
-		if ($x[0] =~ /^(depth|seldepth|hashfull|time|nodes|nps|tbhits)$/) {
+		if ($x[0] eq 'depth' || $x[0] eq 'seldepth' || $x[0] eq 'hashfull' ||
+		    $x[0] eq 'time' || $x[0] eq 'nodes' || $x[0] eq 'nps' ||
+		    $x[0] eq 'tbhits') {
 			my $key = shift @x;
 			my $value = shift @x;
 			$info->{$key . $mpv} = $value;
@@ -281,7 +311,7 @@ sub parse_infos {
 			delete $info->{'score_cp' . $mpv};
 			delete $info->{'score_mate' . $mpv};
 
-			while ($x[0] =~ /^(cp|mate|lowerbound|upperbound)$/) {
+			while ($x[0] eq 'cp' || $x[0] eq 'mate' || $x[0] eq 'lowerbound' || $x[0] eq 'upperbound') {
 				if ($x[0] eq 'cp') {
 					shift @x;
 					$info->{'score_cp' . $mpv} = shift @x;
@@ -325,185 +355,7 @@ sub parse_ids {
 	}
 }
 
-sub style12_to_pos {
-	my $str = shift;
-	my %pos = ();
-	my (@x) = split / /, $str;
-	
-	$pos{'board'} = [ @x[1..8] ];
-	$pos{'toplay'} = $x[9];
-	$pos{'ep_file_num'} = $x[10];
-	$pos{'white_castle_k'} = $x[11];
-	$pos{'white_castle_q'} = $x[12];
-	$pos{'black_castle_k'} = $x[13];
-	$pos{'black_castle_q'} = $x[14];
-	$pos{'time_to_100move_rule'} = $x[15];
-	$pos{'move_num'} = $x[26];
-	$pos{'last_move'} = $x[29];
-	$pos{'fen'} = make_fen(\%pos);
-
-	return \%pos;
-}
-
-sub make_fen {
-	my $pos = shift;
-
-	# the board itself
-	my (@board) = @{$pos->{'board'}};
-	for my $rank (0..7) {
-		$board[$rank] =~ s/(-+)/length($1)/ge;
-	}
-	my $fen = join('/', @board);
-
-	# white/black to move
-	$fen .= " ";
-	$fen .= lc($pos->{'toplay'});
-
-	# castling
-	my $castling = "";
-	$castling .= "K" if ($pos->{'white_castle_k'} == 1);
-	$castling .= "Q" if ($pos->{'white_castle_q'} == 1);
-	$castling .= "k" if ($pos->{'black_castle_k'} == 1);
-	$castling .= "q" if ($pos->{'black_castle_q'} == 1);
-	$castling = "-" if ($castling eq "");
-	# $castling = "-"; # chess960
-	$fen .= " ";
-	$fen .= $castling;
-
-	# en passant
-	my $ep = "-";
-	if ($pos->{'ep_file_num'} != -1) {
-		my $col = $pos->{'ep_file_num'};
-		my $nep = (qw(a b c d e f g h))[$col];
-
-		if ($pos->{'toplay'} eq 'B') {
-			$nep .= "3";
-		} else {
-			$nep .= "6";
-		}
-
-		#
-		# Showing the en passant square when actually no capture can be made
-		# seems to confuse at least Rybka. Thus, check if there's actually
-		# a pawn of the opposite side that can do the en passant move, and if
-		# not, just lie -- it doesn't matter anyway. I'm unsure what's the
-		# "right" thing as per the standard, though.
-		#
-		if ($pos->{'toplay'} eq 'B') {
-			$ep = $nep if ($col > 0 && substr($pos->{'board'}[4], $col-1, 1) eq 'p');
-			$ep = $nep if ($col < 7 && substr($pos->{'board'}[4], $col+1, 1) eq 'p');
-		} else {
-			$ep = $nep if ($col > 0 && substr($pos->{'board'}[3], $col-1, 1) eq 'P');
-			$ep = $nep if ($col < 7 && substr($pos->{'board'}[3], $col+1, 1) eq 'P');
-		}
-	}
-	$fen .= " ";
-	$fen .= $ep;
-
-	# half-move clock
-	$fen .= " ";
-	$fen .= $pos->{'time_to_100move_rule'};
-
-	# full-move clock
-	$fen .= " ";
-	$fen .= $pos->{'move_num'};
-
-	return $fen;
-}
-
-sub make_move {
-	my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
-	my $move = move_to_uci_notation($from_row, $from_col, $to_row, $to_col, $promo);
-	my $piece = substr($board->[$from_row], $from_col, 1);
-	my @nb = @$board;
-
-	if ($piece eq '-') {
-		die "Invalid move $move";
-	}
-
-	# white short castling
-	if ($move eq 'e1g1' && $piece eq 'K') {
-		# king
-		substr($nb[7], 4, 1, '-');
-		substr($nb[7], 6, 1, $piece);
-		
-		# rook
-		substr($nb[7], 7, 1, '-');
-		substr($nb[7], 5, 1, 'R');
-				
-		return \@nb;
-	}
-
-	# white long castling
-	if ($move eq 'e1c1' && $piece eq 'K') {
-		# king
-		substr($nb[7], 4, 1, '-');
-		substr($nb[7], 2, 1, $piece);
-		
-		# rook
-		substr($nb[7], 0, 1, '-');
-		substr($nb[7], 3, 1, 'R');
-				
-		return \@nb;
-	}
-
-	# black short castling
-	if ($move eq 'e8g8' && $piece eq 'k') {
-		# king
-		substr($nb[0], 4, 1, '-');
-		substr($nb[0], 6, 1, $piece);
-		
-		# rook
-		substr($nb[0], 7, 1, '-');
-		substr($nb[0], 5, 1, 'r');
-				
-		return \@nb;
-	}
-
-	# black long castling
-	if ($move eq 'e8c8' && $piece eq 'k') {
-		# king
-		substr($nb[0], 4, 1, '-');
-		substr($nb[0], 2, 1, $piece);
-		
-		# rook
-		substr($nb[0], 0, 1, '-');
-		substr($nb[0], 3, 1, 'r');
-				
-		return \@nb;
-	}
-
-	# check if the from-piece is a pawn
-	if (lc($piece) eq 'p') {
-		# attack?
-		if ($from_col != $to_col) {
-			# en passant?
-			if (substr($board->[$to_row], $to_col, 1) eq '-') {
-				if ($piece eq 'p') {
-					substr($nb[$to_row + 1], $to_col, 1, '-');
-				} else {
-					substr($nb[$to_row - 1], $to_col, 1, '-');
-				}
-			}
-		} else {
-			if ($promo ne '') {
-				if ($piece eq 'p') {
-					$piece = $promo;
-				} else {
-					$piece = uc($promo);
-				}
-			}
-		}
-	}
-
-	# update the board
-	substr($nb[$from_row], $from_col, 1, '-');
-	substr($nb[$to_row], $to_col, 1, $piece);
-
-	return \@nb;
-}
-
-sub prettyprint_pv {
+sub prettyprint_pv_no_cache {
 	my ($board, @pvs) = @_;
 
 	if (scalar @pvs == 0 || !defined($pvs[0])) {
@@ -511,115 +363,25 @@ sub prettyprint_pv {
 	}
 
 	my $pv = shift @pvs;
-	my $from_col = col_letter_to_num(substr($pv, 0, 1));
-	my $from_row = row_letter_to_num(substr($pv, 1, 1));
-	my $to_col   = col_letter_to_num(substr($pv, 2, 1));
-	my $to_row   = row_letter_to_num(substr($pv, 3, 1));
-	my $promo    = substr($pv, 4, 1);
-
-	my $nb = make_move($board, $from_row, $from_col, $to_row, $to_col, $promo);
-	my $piece = substr($board->[$from_row], $from_col, 1);
-
-	if ($piece eq '-') {
-		die "Invalid move $pv";
-	}
-
-	# white short castling
-	if ($pv eq 'e1g1' && $piece eq 'K') {
-		return ('0-0', prettyprint_pv($nb, @pvs));
-	}
-
-	# white long castling
-	if ($pv eq 'e1c1' && $piece eq 'K') {
-		return ('0-0-0', prettyprint_pv($nb, @pvs));
-	}
-
-	# black short castling
-	if ($pv eq 'e8g8' && $piece eq 'k') {
-		return ('0-0', prettyprint_pv($nb, @pvs));
-	}
-
-	# black long castling
-	if ($pv eq 'e8c8' && $piece eq 'k') {
-		return ('0-0-0', prettyprint_pv($nb, @pvs));
-	}
-
-	my $pretty;
-
-	# check if the from-piece is a pawn
-	if (lc($piece) eq 'p') {
-		# attack?
-		if ($from_col != $to_col) {
-			$pretty = substr($pv, 0, 1) . 'x' . substr($pv, 2, 2);
-		} else {
-			$pretty = substr($pv, 2, 2);
+	my ($from_col, $from_row, $to_col, $to_row, $promo) = parse_uci_move($pv);
+	my ($pretty, $nb) = $board->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
+	return ( $pretty, prettyprint_pv_no_cache($nb, @pvs) );
+}
 
-			if (length($pv) == 5) {
-				# promotion
-				$pretty .= "=";
-				$pretty .= uc(substr($pv, 4, 1));
+sub prettyprint_pv {
+	my ($pos, @pvs) = @_;
 
-				if ($piece eq 'p') {
-					$piece = substr($pv, 4, 1);
-				} else {
-					$piece = uc(substr($pv, 4, 1));
-				}
-			}
-		}
+	my $cachekey = join('', @pvs);
+	if (exists($pos->{'prettyprint_cache'}{$cachekey})) {
+		return @{$pos->{'prettyprint_cache'}{$cachekey}};
 	} else {
-		$pretty = uc($piece);
-
-		# see how many of these pieces could go here, in all
-		my $num_total = 0;
-		for my $col (0..7) {
-			for my $row (0..7) {
-				next unless (substr($board->[$row], $col, 1) eq $piece);
-				++$num_total if (can_reach($board, $piece, $row, $col, $to_row, $to_col));
-			}
-		}
-
-		# see how many of these pieces from the given row could go here
-		my $num_row = 0;
-		for my $col (0..7) {
-			next unless (substr($board->[$from_row], $col, 1) eq $piece);
-			++$num_row if (can_reach($board, $piece, $from_row, $col, $to_row, $to_col));
-		}
-		
-		# and same for columns
-		my $num_col = 0;
-		for my $row (0..7) {
-			next unless (substr($board->[$row], $from_col, 1) eq $piece);
-			++$num_col if (can_reach($board, $piece, $row, $from_col, $to_row, $to_col));
-		}
-		
-		# see if we need to disambiguate
-		if ($num_total > 1) {
-			if ($num_col == 1) {
-				$pretty .= substr($pv, 0, 1);
-			} elsif ($num_row == 1) {
-				$pretty .= substr($pv, 1, 1);
-			} else {
-				$pretty .= substr($pv, 0, 2);
-			}
-		}
-
-		# attack?
-		if (substr($board->[$to_row], $to_col, 1) ne '-') {
-			$pretty .= 'x';
-		}
-
-		$pretty .= substr($pv, 2, 2);
-	}
-
-	if (in_mate($nb)) {
-		$pretty .= '#';
-	} elsif (in_check($nb) ne 'none') {
-		$pretty .= '+';
+		my @res = prettyprint_pv_no_cache($pos->{'board'}, @pvs);
+		$pos->{'prettyprint_cache'}{$cachekey} = \@res;
+		return @res;
 	}
-	return ($pretty, prettyprint_pv($nb, @pvs));
 }
 
-sub output_screen {
+sub output {
 	#return;
 
 	return if (!defined($pos_calculating));
@@ -630,11 +392,22 @@ sub output_screen {
 		Time::HiRes::alarm($update_max_interval + 0.01 - $age);
 		return;
 	}
-	$latest_update = [Time::HiRes::gettimeofday];
-
+	
 	my $info = $engine->{'info'};
-	my $id = $engine->{'id'};
-
+	
+	#
+	# Some programs _always_ report MultiPV, even with only one PV.
+	# In this case, we simply use that data as if MultiPV was never
+	# specified.
+	#
+	if (exists($info->{'pv1'}) && !exists($info->{'pv2'})) {
+		for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
+			if (exists($info->{$key . '1'})) {
+				$info->{$key} = $info->{$key . '1'};
+			}
+		}
+	}
+	
 	#
 	# Check the PVs first. if they're invalid, just wait, as our data
 	# is most likely out of sync. This isn't a very good solution, as
@@ -643,12 +416,12 @@ sub output_screen {
 	eval {
 		my $dummy;
 		if (exists($info->{'pv'})) {
-			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}});
+			$dummy = prettyprint_pv($pos_calculating, @{$info->{'pv'}});
 		}
 	
 		my $mpv = 1;
 		while (exists($info->{'pv' . $mpv})) {
-			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}});
+			$dummy = prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}});
 			++$mpv;
 		}
 	};
@@ -657,6 +430,15 @@ sub output_screen {
 		return;
 	}
 
+	output_screen();
+	output_json();
+	$latest_update = [Time::HiRes::gettimeofday];
+}
+
+sub output_screen {
+	my $info = $engine->{'info'};
+	my $id = $engine->{'id'};
+
 	my $text = 'Analysis';
 	if ($pos_calculating->{'last_move'} ne 'none') {
 		if ($pos_calculating->{'toplay'} eq 'W') {
@@ -677,19 +459,6 @@ sub output_screen {
 
 	return unless (exists($pos_calculating->{'board'}));
 		
-	#
-	# Some programs _always_ report MultiPV, even with only one PV.
-	# In this case, we simply use that data as if MultiPV was never
-	# specified.
-	#
-	if (exists($info->{'pv1'}) && !exists($info->{'pv2'})) {
-		for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
-			if (exists($info->{$key . '1'})) {
-				$info->{$key} = $info->{$key . '1'};
-			}
-		}
-	}
-
 	if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
 		# multi-PV
 		my $mpv = 1;
@@ -713,7 +482,7 @@ sub output_screen {
 			}
 
 			$text .= ":\n";
-			$text .= "  " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}})) . "\n";
+			$text .= "  " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}})) . "\n";
 			$text .= "\n";
 			++$mpv;
 		}
@@ -721,48 +490,51 @@ sub output_screen {
 		# single-PV
 		my $score = long_score($info, $pos_calculating, '');
 		$text .= "  $score\n" if defined($score);
-		$text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
+		$text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv'}}));
 		$text .=  "\n";
 
 		if (exists($info->{'nodes'}) && exists($info->{'nps'}) && exists($info->{'depth'})) {
 			$text .= sprintf "  %u nodes, %7u nodes/sec, depth %u ply",
 				$info->{'nodes'}, $info->{'nps'}, $info->{'depth'};
 		}
+		if (exists($info->{'seldepth'})) {
+			$text .= sprintf " (%u selective)", $info->{'seldepth'};
+		}
 		if (exists($info->{'tbhits'}) && $info->{'tbhits'} > 0) {
 			if ($info->{'tbhits'} == 1) {
-				$text .= ", one Nalimov hit";
+				$text .= ", one Syzygy hit";
 			} else {
-				$text .= sprintf ", %u Nalimov hits", $info->{'tbhits'};
+				$text .= sprintf ", %u Syzygy hits", $info->{'tbhits'};
 			}
 		}
-		if (exists($info->{'seldepth'})) {
-			$text .= sprintf " (%u selective)", $info->{'seldepth'};
-		}
 		$text .= "\n\n";
 	}
 
-	#$text .= book_info($pos_calculating->{'fen'}, $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
+	#$text .= book_info($pos_calculating->fen(), $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
 
 	my @refutation_lines = ();
-	for my $move (keys %refutation_moves) {
-		eval {
-			my $m = $refutation_moves{$move};
-			die if ($m->{'depth'} < $second_engine_start_depth);
-			my $pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $move));
-			my @pretty_pv = prettyprint_pv($pos_calculating->{'board'}, $move, @{$m->{'pv'}});
-			if (scalar @pretty_pv > 5) {
-				@pretty_pv = @pretty_pv[0..4];
-				push @pretty_pv, "...";
-			}
-			#my $key = score_sort_key($refutation_moves{$move}, $pos_calculating, '', 1);
-			my $key = $pretty_move;
-			my $line = sprintf("  %-6s %6s %3s  %s",
-				$pretty_move,
-				short_score($refutation_moves{$move}, $pos_calculating, '', 1),
-				"d" . $m->{'depth'},
-				join(', ', @pretty_pv));
-			push @refutation_lines, [ $key, $line ];
-		};
+	if (defined($engine2)) {
+		for (my $mpv = 1; $mpv < 500; ++$mpv) {
+			my $info = $engine2->{'info'};
+			last if (!exists($info->{'pv' . $mpv}));
+			eval {
+				my $pv = $info->{'pv' . $mpv};
+
+				my $pretty_move = join('', prettyprint_pv($pos_calculating_second_engine, $pv->[0]));
+				my @pretty_pv = prettyprint_pv($pos_calculating_second_engine, @$pv);
+				if (scalar @pretty_pv > 5) {
+					@pretty_pv = @pretty_pv[0..4];
+					push @pretty_pv, "...";
+				}
+				my $key = $pretty_move;
+				my $line = sprintf("  %-6s %6s %3s  %s",
+					$pretty_move,
+					short_score($info, $pos_calculating_second_engine, $mpv, 0),
+					"d" . $info->{'depth' . $mpv},
+					join(', ', @pretty_pv));
+				push @refutation_lines, [ $key, $line ];
+			};
+		}
 	}
 
 	if ($#refutation_lines >= 0) {
@@ -778,266 +550,63 @@ sub output_screen {
 		print $text;
 		$last_text = $text;
 	}
-
-	# Now construct the tell text, if any
-	return if (!defined($telltarget));
-
-	my $tell_text = '';
-
-	if (exists($id->{'name'})) {
-		$tell_text .= "Analysis by $id->{'name'} -- see http://analysis.sesse.net/ for more information\n";
-	} else {
-		$tell_text .= "Computer analysis -- http://analysis.sesse.net/ for more information\n";
-	}
-
-	if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
-		# multi-PV
-		my $mpv = 1;
-		while (exists($info->{'pv' . $mpv})) {
-			$tell_text .= sprintf "  PV%2u", $mpv;
-			my $score = short_score($info, $pos_calculating, $mpv);
-			$tell_text .= "  ($score)" if (defined($score));
-
-			if (exists($info->{'depth' . $mpv})) {
-				$tell_text .= sprintf " (%2u ply)", $info->{'depth' . $mpv};
-			}
-
-			$tell_text .= ": ";
-			$tell_text .= join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}}));
-			$tell_text .= "\n";
-			++$mpv;
-		}
-	} else {
-		# single-PV
-		my $score = long_score($info, $pos_calculating, '');
-		$tell_text .= "  $score\n" if defined($score);
-		$tell_text .= "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
-		if (exists($info->{'depth'})) {
-			$tell_text .= sprintf " (depth %u ply)", $info->{'depth'};
-		}
-		$tell_text .=  "\n";
-	}
-
-	# see if a new tell is called for -- it is if the delay has expired _and_
-	# this is not simply a repetition of the last one
-	if ($last_told_text ne $tell_text) {
-		my $now = time;
-		for my $iv (@tell_intervals) {
-			last if ($now - $last_move < $iv);
-			next if ($last_tell - $last_move >= $iv);
-
-			for my $line (split /\n/, $tell_text) {
-				$t->print("tell $telltarget [$target] $line");
-			}
-
-			$last_told_text = $text;
-			$last_tell = $now;
-
-			last;
-		}
-	}
-}
-
-sub find_kings {
-	my $board = shift;
-	my ($wkr, $wkc, $bkr, $bkc);
-
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			if ($piece eq 'K') {
-				($wkr, $wkc) = ($row, $col);
-			} elsif ($piece eq 'k') {
-				($bkr, $bkc) = ($row, $col);
-			}
-		}
-	}
-
-	return ($wkr, $wkc, $bkr, $bkc);
-}
-
-sub in_mate {
-	my $board = shift;
-	my $check = in_check($board);
-	return 0 if ($check eq 'none');
-
-	# try all possible moves for the side in check
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			next if ($piece eq '-');
-
-			if ($check eq 'white') {
-				next if ($piece eq lc($piece));
-			} else {
-				next if ($piece eq uc($piece));
-			}
-
-			for my $dest_row (0..7) {
-				for my $dest_col (0..7) {
-					next if ($row == $dest_row && $col == $dest_col);
-					next unless (can_reach($board, $piece, $row, $col, $dest_row, $dest_col));
-
-					my @nb = @$board;
-					substr($nb[$row], $col, 1, '-');
-					substr($nb[$dest_row], $dest_col, 1, $piece);
-
-					my $new_check = in_check(\@nb);
-					return 0 if ($new_check ne $check && $new_check ne 'both');
-				}
-			}
-		}
-	}
-
-	# nothing to do; mate
-	return 1;
 }
 
-sub in_check {
-	my $board = shift;
-	my ($black_check, $white_check) = (0, 0);
-
-	my ($wkr, $wkc, $bkr, $bkc) = find_kings($board);
-
-	# check all pieces for the possibility of threatening the two kings
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			next if ($piece eq '-');
-		
-			if (uc($piece) eq $piece) {
-				# white piece
-				$black_check = 1 if (can_reach($board, $piece, $row, $col, $bkr, $bkc));
-			} else {
-				# black piece
-				$white_check = 1 if (can_reach($board, $piece, $row, $col, $wkr, $wkc));
-			}
-		}
-	}
-
-	if ($black_check && $white_check) {
-		return 'both';
-	} elsif ($black_check) {
-		return 'black';
-	} elsif ($white_check) {
-		return 'white';
-	} else {
-		return 'none';
-	}
-}
-
-sub can_reach {
-	my ($board, $piece, $from_row, $from_col, $to_row, $to_col) = @_;
-	
-	# can't eat your own piece
-	my $dest_piece = substr($board->[$to_row], $to_col, 1);
-	if ($dest_piece ne '-') {
-		return 0 if (($piece eq lc($piece)) == ($dest_piece eq lc($dest_piece)));
-	}
-
-	if (lc($piece) eq 'k') {
-		return (abs($from_row - $to_row) <= 1 && abs($from_col - $to_col) <= 1);
-	}
-	if (lc($piece) eq 'r') {
-		return 0 unless ($from_row == $to_row || $from_col == $to_col);
-
-		# check that there's a clear passage
-		if ($from_row == $to_row) {
-			if ($from_col > $to_col) {
-				($to_col, $from_col) = ($from_col, $to_col);
-			}
-
-			for my $c (($from_col+1)..($to_col-1)) {
-				my $middle_piece = substr($board->[$to_row], $c, 1);
-				return 0 if ($middle_piece ne '-');	
-			}
-
-			return 1;
-		} else {
-			if ($from_row > $to_row) {
-				($to_row, $from_row) = ($from_row, $to_row);
-			}
-
-			for my $r (($from_row+1)..($to_row-1)) {
-				my $middle_piece = substr($board->[$r], $to_col, 1);
-				return 0 if ($middle_piece ne '-');	
-			}
-
-			return 1;
-		}
-	}
-	if (lc($piece) eq 'b') {
-		return 0 unless (abs($from_row - $to_row) == abs($from_col - $to_col));
-
-		my $dr = ($to_row - $from_row) / abs($to_row - $from_row);
-		my $dc = ($to_col - $from_col) / abs($to_col - $from_col);
+sub output_json {
+	my $info = $engine->{'info'};
 
-		my $r = $from_row + $dr;
-		my $c = $from_col + $dc;
+	my $json = {};
+	$json->{'position'} = $pos_calculating->to_json_hash();
+	$json->{'id'} = $engine->{'id'};
+	$json->{'score'} = long_score($info, $pos_calculating, '');
 
-		while ($r != $to_row) {
-			my $middle_piece = substr($board->[$r], $c, 1);
-			return 0 if ($middle_piece ne '-');
-			
-			$r += $dr;
-			$c += $dc;
-		}
+	$json->{'nodes'} = $info->{'nodes'};
+	$json->{'nps'} = $info->{'nps'};
+	$json->{'depth'} = $info->{'depth'};
+	$json->{'tbhits'} = $info->{'tbhits'};
+	$json->{'seldepth'} = $info->{'seldepth'};
 
-		return 1;
-	}
-	if (lc($piece) eq 'n') {
-		my $diff_r = abs($from_row - $to_row);
-		my $diff_c = abs($from_col - $to_col);
-		return 1 if ($diff_r == 2 && $diff_c == 1);
-		return 1 if ($diff_r == 1 && $diff_c == 2);
-		return 0;
-	}
-	if ($piece eq 'q') {
-		return (can_reach($board, 'r', $from_row, $from_col, $to_row, $to_col) ||
-		        can_reach($board, 'b', $from_row, $from_col, $to_row, $to_col));
-	}
-	if ($piece eq 'Q') {
-		return (can_reach($board, 'R', $from_row, $from_col, $to_row, $to_col) ||
-		        can_reach($board, 'B', $from_row, $from_col, $to_row, $to_col));
-	}
+	# single-PV only for now
+	$json->{'pv_uci'} = $info->{'pv'};
+	$json->{'pv_pretty'} = [ prettyprint_pv($pos_calculating, @{$info->{'pv'}}) ];
 
-	# TODO: en passant
-	if ($piece eq 'p') {
-		# black pawn
-		if ($to_col == $from_col && $to_row == $from_row + 1) {
-			return ($dest_piece eq '-');
-		}
-		if ($to_col == $from_col && $from_row == 1 && $to_row == 3) {
-			my $middle_piece = substr($board->[2], $to_col, 1);
-			return ($dest_piece eq '-' && $middle_piece eq '-');
-		}
-		if (abs($to_col - $from_col) == 1 && $to_row == $from_row + 1) {
-			return ($dest_piece ne '-');
-		}
-		return 0;
-	}
-	if ($piece eq 'P') {
-		# white pawn
-		if ($to_col == $from_col && $to_row == $from_row - 1) {
-			return ($dest_piece eq '-');
-		}
-		if ($to_col == $from_col && $from_row == 6 && $to_row == 4) {
-			my $middle_piece = substr($board->[5], $to_col, 1);
-			return ($dest_piece eq '-' && $middle_piece eq '-');
-		}
-		if (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
-			return ($dest_piece ne '-');
-		}
-		return 0;
-	}
-	
-	# unknown piece
-	return 0;
+	my %refutation_lines = ();
+	my @refutation_lines = ();
+	if (defined($engine2)) {
+		for (my $mpv = 1; $mpv < 500; ++$mpv) {
+			my $info = $engine2->{'info'};
+			my $pretty_move = "";
+			my @pretty_pv = ();
+			last if (!exists($info->{'pv' . $mpv}));
+
+			eval {
+				my $pv = $info->{'pv' . $mpv};
+				my $pretty_move = join('', prettyprint_pv($pos_calculating, $pv->[0]));
+				my @pretty_pv = prettyprint_pv($pos_calculating, @$pv);
+				$refutation_lines{$pv->[0]} = {
+					sort_key => $pretty_move,
+					depth => $info->{'depth' . $mpv},
+					score_sort_key => score_sort_key($info, $pos_calculating, $mpv, 0),
+					pretty_score => short_score($info, $pos_calculating, $mpv, 0),
+					pretty_move => $pretty_move,
+					pv_pretty => \@pretty_pv,
+				};
+				$refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
+			};
+		}
+	}
+	$json->{'refutation_lines'} = \%refutation_lines;
+
+	open my $fh, ">/srv/analysis.sesse.net/www/analysis.json.tmp"
+		or return;
+	print $fh JSON::XS::encode_json($json);
+	close $fh;
+	rename("/srv/analysis.sesse.net/www/analysis.json.tmp", "/srv/analysis.sesse.net/www/analysis.json");
 }
 
 sub uciprint {
 	my ($engine, $msg) = @_;
-	print { $engine->{'write'} } "$msg\n";
+	$engine->print($msg);
 	print UCILOG localtime() . " $engine->{'tag'} => $msg\n";
 }
 
@@ -1051,9 +620,9 @@ sub short_score {
 
 	if (defined($info->{'score_mate' . $mpv})) {
 		if ($invert) {
-			return sprintf "M%3d", $info->{'score_mate' . $mpv};
-		} else {
 			return sprintf "M%3d", -$info->{'score_mate' . $mpv};
+		} else {
+			return sprintf "M%3d", $info->{'score_mate' . $mpv};
 		}
 	} else {
 		if (exists($info->{'score_cp' . $mpv})) {
@@ -1074,16 +643,11 @@ sub short_score {
 sub score_sort_key {
 	my ($info, $pos, $mpv, $invert) = @_;
 
-	$invert //= 0;
-	if ($pos->{'toplay'} eq 'B') {
-		$invert = !$invert;
-	}
-
 	if (defined($info->{'score_mate' . $mpv})) {
 		if ($invert) {
-			return -(99999 - $info->{'score_mate' . $mpv});
-		} else {
 			return 99999 - $info->{'score_mate' . $mpv};
+		} else {
+			return -(99999 - $info->{'score_mate' . $mpv});
 		}
 	} else {
 		if (exists($info->{'score_cp' . $mpv})) {
@@ -1114,6 +678,9 @@ sub long_score {
 	} else {
 		if (exists($info->{'score_cp' . $mpv})) {
 			my $score = $info->{'score_cp' . $mpv} * 0.01;
+			if ($score == 0) {
+				return "Score:  0.00";
+			}
 			if ($pos->{'toplay'} eq 'B') {
 				$score = -$score;
 			}
@@ -1144,7 +711,7 @@ sub book_info {
 		if ($move eq '')  {
 			$pmove = '(current)';
 		} else {
-			($pmove) = prettyprint_pv($board, $move);
+			($pmove) = prettyprint_pv_no_cache($board, $move);
 			$pmove .= $annotation;
 		}
 
@@ -1177,129 +744,9 @@ sub book_info {
 }
 
 sub open_engine {
-	my ($cmdline, $tag) = @_;
-	my ($uciread, $uciwrite);
-	my $pid = IPC::Open2::open2($uciread, $uciwrite, $cmdline);
-
-	my $engine = {
-		pid => $pid,
-		read => $uciread,
-		readbuf => '',
-		write => $uciwrite,
-		info => {},
-		ids => {},
-		tag => $tag,
-	};
-
-	uciprint($engine, "uci");
-
-	# gobble the options
-	while (<$uciread>) {
-		/uciok/ && last;
-		handle_uci($engine, $_);
-	}
-	
-	return $engine;
-}
-
-sub read_lines {
-	my $engine = shift;
-
-	# 
-	# Read until we've got a full line -- if the engine sends part of
-	# a line and then stops we're pretty much hosed, but that should
-	# never happen.
-	#
-	while ($engine->{'readbuf'} !~ /\n/) {
-		my $tmp;
-		my $ret = sysread $engine->{'read'}, $tmp, 4096;
-
-		if (!defined($ret)) {
-			next if ($!{EINTR});
-			die "error in reading from the UCI engine: $!";
-		} elsif ($ret == 0) {
-			die "EOF from UCI engine";
-		}
-
-		$engine->{'readbuf'} .= $tmp;
-	}
-
-	# Blah.
-	my @lines = ();
-	while ($engine->{'readbuf'} =~ s/^([^\n]*)\n//) {
-		my $line = $1;
-		$line =~ tr/\r\n//d;
-		push @lines, $line;
-	}
-	return @lines;
-}
-
-# Find all possible legal moves.
-sub calculate_refutation_moves {
-	my $pos = shift;
-	my $board = $pos->{'board'};
-	my %refutation_moves = ();
-	for my $col (0..7) {
-		for my $row (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-
-			# Check that there's a piece of the right color on this square.
-			next if ($piece eq '-');
-			if ($pos->{'toplay'} eq 'W') {
-				next if ($piece ne uc($piece));
-			} else {
-				next if ($piece ne lc($piece));
-			}
-
-			for my $to_col (0..7) {
-				for my $to_row (0..7) {
-					next if ($col == $to_col && $row == $to_row);
-					next unless (can_reach($board, $piece, $row, $col, $to_row, $to_col));
-
-					my $promo = "";  # FIXME
-					my $nb = make_move($board, $row, $col, $to_row, $to_col, $promo);
-					my $check = in_check($nb);
-					next if ($check eq 'both');
-					if ($pos->{'toplay'} eq 'W') {
-						next if ($check eq 'white');
-					} else {
-						next if ($check eq 'black');
-					}
-					my $move = move_to_uci_notation($row, $col, $to_row, $to_col, $promo);
-					$refutation_moves{$move} = { depth => $second_engine_start_depth - 1, score_cp => 0, pv => '' };
-				}
-			}
-		}
-	}
-	return %refutation_moves;
-}
-
-sub give_new_move_to_second_engine {
-	my $pos = shift;
-				
-	# Find the move that's been analyzed the shortest but is most promising.
-	# Tie-break on UCI move representation.
-	my $best_move = undef;
-	for my $move (sort keys %refutation_moves) {
-		if (!defined($best_move)) {
-			$best_move = $move;
-			next;
-		}
-		my $best = $refutation_moves{$best_move};
-		my $this = $refutation_moves{$move};
-
-		if ($this->{'depth'} < $best->{'depth'} ||
-		    ($this->{'depth'} == $best->{'depth'} && $this->{'score_cp'} < $best->{'score_cp'})) {
-			$best_move = $move;
-			next;
-		}
-	}
-
-	my $m = $refutation_moves{$best_move};
-	++$m->{'depth'};
-	uciprint($engine2, "position fen " . $pos->{'fen'} . " moves " . $best_move);
-	uciprint($engine2, "go depth " . $m->{'depth'});
-	$move_calculating_second_engine = $best_move;
+	my ($cmdline, $tag, $cb) = @_;
+	return undef if (!defined($cmdline));
+	return Engine->open($cmdline, $tag, $cb);
 }
 
 sub col_letter_to_num {
@@ -1310,8 +757,12 @@ sub row_letter_to_num {
 	return 7 - (ord(shift) - ord('1'));
 }
 
-sub move_to_uci_notation {
-	my ($from_row, $from_col, $to_row, $to_col, $promo) = @_;
-	$promo //= "";
-	return sprintf("%c%d%c%d%s", ord('a') + $from_col, 8 - $from_row, ord('a') + $to_col, 8 - $to_row, $promo);
+sub parse_uci_move {
+	my $move = shift;
+	my $from_col = col_letter_to_num(substr($move, 0, 1));
+	my $from_row = row_letter_to_num(substr($move, 1, 1));
+	my $to_col   = col_letter_to_num(substr($move, 2, 1));
+	my $to_row   = row_letter_to_num(substr($move, 3, 1));
+	my $promo    = substr($move, 4, 1);
+	return ($from_col, $from_row, $to_col, $to_row, $promo);
 }