diff options
| -rw-r--r-- | FICS/ratings.c | 155 |
1 files changed, 79 insertions, 76 deletions
diff --git a/FICS/ratings.c b/FICS/ratings.c index 4178c36..d20355a 100644 --- a/FICS/ratings.c +++ b/FICS/ratings.c @@ -499,92 +499,95 @@ PUBLIC double current_sterr(double s, int t) return (sqrt(s * s + Gd * Gd * log(1.0 + t / 60.0))); } -/* Calculates new rating and standard error. By vek. The person */ -/* who invented the ratings system is Mark E. Glickman, Ph.D. */ -/* His e-mail address is glickman@hustat.harvard.edu as of April '95. */ -/* Postscript copy of the note I coded this from should be available */ -/* for ftp from ics.onenet.net, if not elsewhere. */ - -PUBLIC void rating_sterr_delta(int p1, int p2, int type, int gtime, int result, - int *deltarating, double *newsterr) +/* + * Calculates new rating and standard error. By vek. The person who + * invented the ratings system is Mark E. Glickman, Ph.D. His e-mail + * address is glickman@hustat.harvard.edu as of April '95. Postscript + * copy of the note I coded this from should be available for ftp from + * ics.onenet.net, if not elsewhere. + */ +PUBLIC void +rating_sterr_delta(int p1, int p2, int type, int gtime, int result, + int *deltarating, double *newsterr) { - statistics *p1_stats; - statistics *p2_stats; - - double s1, s2; - int t1, r1, t2, r2; /* Initial sterrs and ratings */ - double E, fs2, denominator, GK, w; /* Parts of fancy formulas */ - double delta, sigma; /* Results to return */ - - if (type == TYPE_BLITZ) { - p1_stats = &parray[p1].b_stats; - p2_stats = &parray[p2].b_stats; - } else if (type == TYPE_WILD) { - p1_stats = &parray[p1].w_stats; - p2_stats = &parray[p2].w_stats; - } else if (type == TYPE_LIGHT) { - p1_stats = &parray[p1].l_stats; - p2_stats = &parray[p2].l_stats; -/* insert bughouse stuff here */ - } else { - p1_stats = &parray[p1].s_stats; - p2_stats = &parray[p2].s_stats; - } - - /* Calculate effective pre-game sterrs. ltime==0 implies never had sterr. */ + double E, fs2, denominator, GK, w; // Parts of fancy formulas + double delta, sigma; // Results to return + double s1, s2; + int t1, r1, t2, r2; // Initial sterrs and ratings + statistics *p1_stats; + statistics *p2_stats; + + if (type == TYPE_BLITZ) { + p1_stats = &parray[p1].b_stats; + p2_stats = &parray[p2].b_stats; + } else if (type == TYPE_WILD) { + p1_stats = &parray[p1].w_stats; + p2_stats = &parray[p2].w_stats; + } else if (type == TYPE_LIGHT) { + p1_stats = &parray[p1].l_stats; + p2_stats = &parray[p2].l_stats; + + // insert bughouse stuff here + } else { + p1_stats = &parray[p1].s_stats; + p2_stats = &parray[p2].s_stats; + } - if (p1_stats->ltime == 0) - s1 = Gs0; - else { - t1 = gtime - p1_stats->ltime; - s1 = current_sterr(p1_stats->sterr, t1); - if (s1 > Gs0) - s1 = Gs0; - } + /* + * Calculate effective pre-game sterr's. ltime == 0 implies + * never had sterr. + */ + if (p1_stats->ltime == 0) + s1 = Gs0; + else { + t1 = gtime - p1_stats->ltime; + s1 = current_sterr(p1_stats->sterr, t1); + + if (s1 > Gs0) + s1 = Gs0; + } - if (p2_stats->ltime == 0) - s2 = Gs0; - else { - t2 = gtime - p2_stats->ltime; - s2 = current_sterr(p2_stats->sterr, t2); - if (s2 > Gs0) - s2 = Gs0; - } + if (p2_stats->ltime == 0) + s2 = Gs0; + else { + t2 = gtime - p2_stats->ltime; + s2 = current_sterr(p2_stats->sterr, t2); - /* pre-game ratings */ - if (p1_stats->rating == 0 && p1_stats->num == 0) - r1 = Gr0; - else - r1 = p1_stats->rating; + if (s2 > Gs0) + s2 = Gs0; + } - if (p2_stats->rating == 0 && p2_stats->num == 0) - r2 = Gr0; - else - r2 = p2_stats->rating; + if (p1_stats->rating == 0 && p1_stats->num == 0) + r1 = Gr0; + else + r1 = p1_stats->rating; - /* now crunch */ + if (p2_stats->rating == 0 && p2_stats->num == 0) + r2 = Gr0; + else + r2 = p2_stats->rating; - if (result == RESULT_WIN) { - w = 1.0; - } else if (result == RESULT_DRAW) { - w = 0.5; - } else { - w = 0.0; - } + if (result == RESULT_WIN) { + w = 1.0; + } else if (result == RESULT_DRAW) { + w = 0.5; + } else { + w = 0.0; + } - E = GE(r1, r2, s2, &fs2); /* side effect: calculate fs2 */ + E = GE(r1, r2, s2, &fs2); + denominator = 1.0 / (s1 * s1) + Gq * Gq * fs2 * fs2 * E * (1.0 - E); + GK = Gq * fs2 / denominator; + delta = GK * (w - E); - denominator = 1.0 / (s1 * s1) + Gq * Gq * fs2 * fs2 * E * (1.0 - E); - GK = Gq * fs2 / denominator; + if (p1_stats->rating == 0 && p1_stats->num == 0) + *deltarating = Round(Gr0 + delta); + else + *deltarating = Round(delta); // Returned values: deltarating, + // newsterr. - delta = GK * (w - E); - if (p1_stats->rating == 0 && p1_stats->num == 0) - *deltarating = Round(Gr0 + delta); - else - *deltarating = Round(delta); /* Returned values: deltarating, - newsterr */ - sigma = 1.0 / sqrt(denominator); - *newsterr = (double) sigma; + sigma = 1.0 / sqrt(denominator); + *newsterr = (double) sigma; } PUBLIC int |