From 63503a1ac42bc03c97642b1ccbc07b2cfdad7a98 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sesse@debian.org>
Date: Sun, 2 Dec 2007 12:45:59 +0100
Subject: [PATCH] Make the initial rating/RD constants instead of hard-coded
 values.

---
 foosball.pm             |  4 ++--
 foosrank.cpp            | 13 +++++++++++--
 recalc-single-result.pl | 12 ++++++++++--
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/foosball.pm b/foosball.pm
index 58e468c..b40b9fd 100644
--- a/foosball.pm
+++ b/foosball.pm
@@ -75,11 +75,11 @@ sub calc_rating {
 	my ($rating1, $rd1, $rating2, $rd2, $score1, $score2) = @_;
 	my $result = `/srv/foosball.sesse.net/foosrank $rating1 $rd1 $rating2 $rd2 $score1 $score2`;
 	chomp $result;
-	my ($newr1, $newrd1) = split / /, $result;
+	my ($newr1, $newrd1, $likelihood) = split / /, $result;
 
 	$newrd1 = 30.0 if ($newrd1 < 30.0);
 
-	return ($newr1, $newrd1);
+	return ($newr1, $newrd1, $likelihood);
 }
 
 sub calc_rating_double {
diff --git a/foosrank.cpp b/foosrank.cpp
index 99f88b0..67aee58 100644
--- a/foosrank.cpp
+++ b/foosrank.cpp
@@ -484,7 +484,11 @@ int main(int argc, char **argv)
 		int score2 = atoi(argv[10]);
 		double mu, sigma;
 		compute_new_double_rating(mu1, sigma1, mu2, sigma2, mu3, sigma3, mu4, sigma4, score1, score2, mu, sigma);
-		printf("%f %f\n", mu, sigma);
+		if (score1 > score2) {
+			printf("%f %f %f\n", mu, sigma, prob_score(score1, score2, mu3+mu4-(mu1+mu2)));
+		} else {
+			printf("%f %f %f\n", mu, sigma, prob_score(score2, score1, mu1+mu2-(mu3+mu4)));
+		}
 	} else if (argc > 8) {
 		double mu3 = atof(argv[5]);
 		double sigma3 = atof(argv[6]);
@@ -520,7 +524,12 @@ int main(int argc, char **argv)
 		int score2 = atoi(argv[6]);
 		double mu, sigma;
 		compute_new_rating(mu1, sigma1, mu2, sigma2, score1, score2, mu, sigma);
-		printf("%f %f\n", mu, sigma);
+
+		if (score1 > score2) {
+			printf("%f %f %f\n", mu, sigma, prob_score(score1, score2, mu2-mu1));
+		} else {
+			printf("%f %f %f\n", mu, sigma, prob_score(score2, score1, mu1-mu2));
+		}
 	} else {
 		int k = atoi(argv[5]);
 
diff --git a/recalc-single-result.pl b/recalc-single-result.pl
index c67be84..6794787 100755
--- a/recalc-single-result.pl
+++ b/recalc-single-result.pl
@@ -15,6 +15,9 @@ my %ratings = ();
 my $q = $dbh->prepare('select *,extract(epoch from gametime) as eptime from single_results order by gametime');
 $q->execute;
 
+# Combined log-likelihood
+my $cll = 0.0;
+
 while (my $ref = $q->fetchrow_hashref) {
 	for my $user (($ref->{'username1'}, $ref->{'username2'})) {
 		if (!exists($ratings{$user})) {
@@ -36,10 +39,12 @@ while (my $ref = $q->fetchrow_hashref) {
 	$rd1 = foosball::apply_aging($rd1, $age1 / 86400.0);
 	$rd2 = foosball::apply_aging($rd2, $age2 / 86400.0);
 
-	my ($newr1, $newrd1) = foosball::calc_rating($rating1, $rd1, $rating2, $rd2, $score1, $score2);
+	my ($newr1, $newrd1, $likelihood) = foosball::calc_rating($rating1, $rd1, $rating2, $rd2, $score1, $score2);
 	my ($newr2, $newrd2) = foosball::calc_rating($rating2, $rd2, $rating1, $rd1, $score2, $score1);
 
-	printf("%-10s - %-10s: %u - %u, new ratings %u/%u %u/%u\n",
+	$cll += log($likelihood);
+
+	printf("%-10s - %-10s: %u - %u, new ratings %u/%u %u/%u [$likelihood]\n",
 		$ref->{'username1'}, $ref->{'username2'}, $ref->{'score1'},
 		$ref->{'score2'}, $newr1, $newrd1, $newr2, $newrd2);
 	$dbh->do('insert into single_rating values (?,?,?,?,?)', undef,
@@ -53,3 +58,6 @@ while (my $ref = $q->fetchrow_hashref) {
 
 $dbh->commit;
 $dbh->disconnect;
+
+printf "\nCombined negative log-likelihood (smaller value means a better model): %f\n",
+	-$cll;
-- 
2.39.2