my $pos = Position->from_fen($fen);
my $hex = unpack('H*', $pos->bitpacked_fen);
print $chld_in $hex, "\n";
-my $line = <$chld_out>;
+chomp (my $line = <$chld_out>);
my ($white, $draw, $black, $opening_num, $white_avg_elo, $black_avg_elo, $num_elo, $timestamp, @moves) = split / /, $line;
my $opening = $openings{$opening_num} // 'A00: Start position';