uct/dynkomi.c

   1 #define DEBUG
   2 #include <assert.h>
   3 #include <math.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "board.h"
   9 #include "debug.h"
  10 #include "tactics/util.h"
  11 #include "uct/dynkomi.h"
  12 #include "uct/internal.h"
  13 #include "uct/tree.h"
  14
  15
  16 static void
  17 generic_done(struct uct_dynkomi *d)
  18 {
  19         if (d->data) free(d->data);
  20         free(d);
  21 }
  22
  23
  24 /* NONE dynkomi strategy - never fiddle with komi values. */
  25
  26 struct uct_dynkomi *
  27 uct_dynkomi_init_none(struct uct *u, char *arg, struct board *b)
  28 {
  29         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
  30         d->uct = u;
  31         d->permove = NULL;
  32         d->persim = NULL;
  33         d->done = generic_done;
  34         d->data = NULL;
  35
  36         if (arg) {
  37                 fprintf(stderr, "uct: Dynkomi method none accepts no arguments\n");
  38                 exit(1);
  39         }
  40
  41         return d;
  42 }
  43
  44
  45 /* LINEAR dynkomi strategy - Linearly Decreasing Handicap Compensation. */
  46 /* At move 0, we impose extra komi of handicap_count*handicap_value, then
  47  * we linearly decrease this extra komi throughout the game down to 0
  48  * at @moves moves. Towards the end of the game the linear compensation
  49  * becomes zero but we increase the extra komi when winning big. This reduces
  50  * the number of point-wasting moves and makes the game more enjoyable for humans. */
  51
  52 struct dynkomi_linear {
  53         int handicap_value[S_MAX];
  54         int moves[S_MAX];
  55         bool rootbased;
  56         /* Increase the extra komi if my win ratio  > green_zone but always
  57          * keep extra_komi <= komi_ratchet. komi_ratchet starts infinite but decreases
  58          * when we give too much extra komi and this puts us back < orange_zone.
  59          * This is meant only to increase the territory margin when playing against
  60          * weaker opponents. We never take negative komi when losing. The ratchet helps
  61          * avoiding oscillations and keeping us above orange_zone.
  62          * To disable the adaptive phase, set green_zone=2. */
  63         floating_t komi_ratchet;
  64         floating_t green_zone;
  65         floating_t orange_zone;
  66         floating_t drop_step;
  67 };
  68
  69 static floating_t
  70 linear_simple(struct dynkomi_linear *l, struct board *b, enum stone color)
  71 {
  72         int lmoves = l->moves[color];
  73         floating_t base_komi = board_effective_handicap(b, l->handicap_value[color]);
  74         return base_komi * (lmoves - b->moves) / lmoves;
  75 }
  76
  77 static floating_t
  78 linear_permove(struct uct_dynkomi *d, struct board *b, struct tree *tree)
  79 {
  80         struct dynkomi_linear *l = d->data;
  81         enum stone color = d->uct->pondering ? tree->root_color : stone_other(tree->root_color);
  82         int lmoves = l->moves[color];
  83
  84         if (b->moves < lmoves)
  85                 return linear_simple(l, b, color);
  86
  87         /* Allow simple adaptation in extreme endgame situations. */
  88
  89         floating_t extra_komi = floor(tree->extra_komi);
  90
  91         /* Do not take decisions on unstable value. */
  92         if (tree->root->u.playouts < GJ_MINGAMES)
  93                 return extra_komi;
  94
  95         floating_t my_value = tree_node_get_value(tree, 1, tree->root->u.value);
  96         /*  We normalize komi as in komi_by_value(), > 0 when winning. */
  97         extra_komi = komi_by_color(extra_komi, color);
  98         if (extra_komi < 0 && DEBUGL(3))
  99                 fprintf(stderr, "XXX: extra_komi %.3f < 0 (color %s tree ek %.3f)\n", extra_komi, stone2str(color), tree->extra_komi);
 100         // assert(extra_komi >= 0);
 101         floating_t orig_komi = extra_komi;
 102
 103         if (my_value < 0.5 && l->komi_ratchet > 0 && l->komi_ratchet != INFINITY) {
 104                 if (DEBUGL(0))
 105                         fprintf(stderr, "losing %f extra komi %.1f ratchet %.1f -> 0\n",
 106                                 my_value, extra_komi, l->komi_ratchet);
 107                 /* Disable dynkomi completely, too dangerous in this game. */
 108                 extra_komi = l->komi_ratchet = 0;
 109
 110         } else if (my_value < l->orange_zone && extra_komi > 0) {
 111                 extra_komi = l->komi_ratchet  = fmax(extra_komi - l->drop_step, 0.0);
 112                 if (extra_komi != orig_komi && DEBUGL(3))
 113                         fprintf(stderr, "dropping to %f, extra komi %.1f -> %.1f\n",
 114                                 my_value, orig_komi, extra_komi);
 115
 116         } else if (my_value > l->green_zone && extra_komi + 1 <= l->komi_ratchet) {
 117                 extra_komi += 1;
 118                 if (extra_komi != orig_komi && DEBUGL(3))
 119                         fprintf(stderr, "winning %f extra_komi %.1f -> %.1f, ratchet %.1f\n",
 120                                 my_value, orig_komi, extra_komi, l->komi_ratchet);
 121         }
 122         return komi_by_color(extra_komi, color);
 123 }
 124
 125 static floating_t
 126 linear_persim(struct uct_dynkomi *d, struct board *b, struct tree *tree, struct tree_node *node)
 127 {
 128         struct dynkomi_linear *l = d->data;
 129         if (l->rootbased)
 130                 return tree->extra_komi;
 131
 132         /* We don't reuse computed value from tree->extra_komi,
 133          * since we want to use value correct for this node depth.
 134          * This also means the values will stay correct after
 135          * node promotion. */
 136
 137         enum stone color = d->uct->pondering ? tree->root_color : stone_other(tree->root_color);
 138         int lmoves = l->moves[color];
 139         if (b->moves < lmoves)
 140                 return linear_simple(l, b, color);
 141         return tree->extra_komi;
 142 }
 143
 144 struct uct_dynkomi *
 145 uct_dynkomi_init_linear(struct uct *u, char *arg, struct board *b)
 146 {
 147         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
 148         d->uct = u;
 149         d->permove = linear_permove;
 150         d->persim = linear_persim;
 151         d->done = generic_done;
 152
 153         struct dynkomi_linear *l = calloc2(1, sizeof(*l));
 154         d->data = l;
 155
 156         /* Force white to feel behind and try harder, but not to the
 157          * point of resigning immediately in high handicap games.
 158          * By move 100 white should still be behind but should have
 159          * caught up enough to avoid resigning. */
 160         int moves = board_large(b) ? 100 : 50;
 161         if (!board_small(b)) {
 162                 l->moves[S_BLACK] = moves;
 163                 l->moves[S_WHITE] = moves;
 164         }
 165
 166         /* The real value of one stone is twice the komi so about 15 points.
 167          * But use a lower value to avoid being too pessimistic as black
 168          * or too optimistic as white. */
 169         l->handicap_value[S_BLACK] = 8;
 170         l->handicap_value[S_WHITE] = 1;
 171
 172         l->komi_ratchet = INFINITY;
 173         l->green_zone = 0.85;
 174         l->orange_zone = 0.8;
 175         l->drop_step = 4.0;
 176
 177         if (arg) {
 178                 char *optspec, *next = arg;
 179                 while (*next) {
 180                         optspec = next;
 181                         next += strcspn(next, ":");
 182                         if (*next) { *next++ = 0; } else { *next = 0; }
 183
 184                         char *optname = optspec;
 185                         char *optval = strchr(optspec, '=');
 186                         if (optval) *optval++ = 0;
 187
 188                         if (!strcasecmp(optname, "moves") && optval) {
 189                                 /* Dynamic komi in handicap game; linearly
 190                                  * decreases to basic settings until move
 191                                  * #optval. moves=blackmoves%whitemoves */
 192                                 for (int i = S_BLACK; *optval && i <= S_WHITE; i++) {
 193                                         l->moves[i] = atoi(optval);
 194                                         optval += strcspn(optval, "%");
 195                                         if (*optval) optval++;
 196                                 }
 197                         } else if (!strcasecmp(optname, "handicap_value") && optval) {
 198                                 /* Point value of single handicap stone,
 199                                  * for dynkomi computation. */
 200                                 for (int i = S_BLACK; *optval && i <= S_WHITE; i++) {
 201                                         l->handicap_value[i] = atoi(optval);
 202                                         optval += strcspn(optval, "%");
 203                                         if (*optval) optval++;
 204                                 }
 205                         } else if (!strcasecmp(optname, "rootbased")) {
 206                                 /* If set, the extra komi applied will be
 207                                  * the same for all simulations within a move,
 208                                  * instead of being same for all simulations
 209                                  * within the tree node. */
 210                                 l->rootbased = !optval || atoi(optval);
 211                         } else if (!strcasecmp(optname, "green_zone") && optval) {
 212                                 /* Increase komi when win ratio is above green_zone */
 213                                 l->green_zone = atof(optval);
 214                         } else if (!strcasecmp(optname, "orange_zone") && optval) {
 215                                 /* Decrease komi when > 0 and win ratio is below orange_zone */
 216                                 l->orange_zone = atof(optval);
 217                         } else if (!strcasecmp(optname, "drop_step") && optval) {
 218                                 /* Decrease komi by drop_step points */
 219                                 l->drop_step = atof(optval);
 220                         } else {
 221                                 fprintf(stderr, "uct: Invalid dynkomi argument %s or missing value\n", optname);
 222                                 exit(1);
 223                         }
 224                 }
 225         }
 226
 227         return d;
 228 }
 229
 230
 231 /* ADAPTIVE dynkomi strategy - Adaptive Situational Compensation */
 232 /* We adapt the komi based on current situation:
 233  * (i) score-based: We maintain the average score outcome of our
 234  * games and adjust the komi by a fractional step towards the expected
 235  * score;
 236  * (ii) value-based: While winrate is above given threshold, adjust
 237  * the komi by a fixed step in the appropriate direction.
 238  * These adjustments can be
 239  * (a) Move-stepped, new extra komi value is always set only at the
 240  * beginning of the tree search for next move;
 241  * (b) Continuous, new extra komi value is periodically re-determined
 242  * and adjusted throughout a single tree search. */
 243
 244 struct dynkomi_adaptive {
 245         /* Do not take measured average score into regard for
 246          * first @lead_moves - the variance is just too much.
 247          * (Instead, we consider the handicap-based komi provided
 248          * by linear dynkomi.) */
 249         int lead_moves;
 250         /* Maximum komi to pretend the opponent to give. */
 251         floating_t max_losing_komi;
 252         /* Game portion at which losing komi is not allowed anymore. */
 253         floating_t losing_komi_stop;
 254         /* Turn off dynkomi at the (perceived) closing of the game
 255          * (last few moves). */
 256         bool no_komi_at_game_end;
 257         /* Alternative game portion determination. */
 258         bool adapt_aport;
 259         floating_t (*indicator)(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color);
 260
 261         /* Value-based adaptation. */
 262         floating_t zone_red, zone_green;
 263         int score_step;
 264         floating_t score_step_byavg; // use portion of average score as increment
 265         bool use_komi_ratchet;
 266         bool losing_komi_ratchet; // ratchet even losing komi
 267         int komi_ratchet_maxage;
 268         // runtime, not configuration:
 269         int komi_ratchet_age;
 270         floating_t komi_ratchet;
 271
 272         /* Score-based adaptation. */
 273         floating_t (*adapter)(struct uct_dynkomi *d, struct board *b);
 274         floating_t adapt_base; // [0,1)
 275         /* Sigmoid adaptation rate parameter; see below for details. */
 276         floating_t adapt_phase; // [0,1]
 277         floating_t adapt_rate; // [1,infty)
 278         /* Linear adaptation rate parameter. */
 279         int adapt_moves;
 280         floating_t adapt_dir; // [-1,1]
 281 };
 282 #define TRUSTWORTHY_KOMI_PLAYOUTS 200
 283
 284 static floating_t
 285 board_game_portion(struct dynkomi_adaptive *a, struct board *b)
 286 {
 287         if (!a->adapt_aport) {
 288                 int total_moves = b->moves + 2 * board_estimated_moves_left(b);
 289                 return (floating_t) b->moves / total_moves;
 290         } else {
 291                 int brsize = board_size(b) - 2;
 292                 return 1.0 - (floating_t) b->flen / (brsize * brsize);
 293         }
 294 }
 295
 296 static floating_t
 297 adapter_sigmoid(struct uct_dynkomi *d, struct board *b)
 298 {
 299         struct dynkomi_adaptive *a = d->data;
 300         /* Figure out how much to adjust the komi based on the game
 301          * stage. The adaptation rate is 0 at the beginning,
 302          * at game stage a->adapt_phase crosses though 0.5 and
 303          * approaches 1 at the game end; the slope is controlled
 304          * by a->adapt_rate. */
 305         floating_t game_portion = board_game_portion(a, b);
 306         floating_t l = game_portion - a->adapt_phase;
 307         return 1.0 / (1.0 + exp(-a->adapt_rate * l));
 308 }
 309
 310 static floating_t
 311 adapter_linear(struct uct_dynkomi *d, struct board *b)
 312 {
 313         struct dynkomi_adaptive *a = d->data;
 314         /* Figure out how much to adjust the komi based on the game
 315          * stage. We just linearly increase/decrease the adaptation
 316          * rate for first N moves. */
 317         if (b->moves > a->adapt_moves)
 318                 return 0;
 319         if (a->adapt_dir < 0)
 320                 return 1 - (- a->adapt_dir) * b->moves / a->adapt_moves;
 321         else
 322                 return a->adapt_dir * b->moves / a->adapt_moves;
 323 }
 324
 325 static floating_t
 326 komi_by_score(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color)
 327 {
 328         struct dynkomi_adaptive *a = d->data;
 329         if (d->score.playouts < TRUSTWORTHY_KOMI_PLAYOUTS)
 330                 return tree->extra_komi;
 331
 332         struct move_stats score = d->score;
 333         /* Almost-reset tree->score to gather fresh stats. */
 334         d->score.playouts = 1;
 335
 336         /* Look at average score and push extra_komi in that direction. */
 337         floating_t p = a->adapter(d, b);
 338         p = a->adapt_base + p * (1 - a->adapt_base);
 339         if (p > 0.9) p = 0.9; // don't get too eager!
 340         floating_t extra_komi = tree->extra_komi + p * score.value;
 341         if (DEBUGL(3))
 342                 fprintf(stderr, "mC += %f * %f\n", p, score.value);
 343         return extra_komi;
 344 }
 345
 346 static floating_t
 347 komi_by_value(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color)
 348 {
 349         struct dynkomi_adaptive *a = d->data;
 350         if (d->value.playouts < TRUSTWORTHY_KOMI_PLAYOUTS)
 351                 return tree->extra_komi;
 352
 353         struct move_stats value = d->value;
 354         /* Almost-reset tree->value to gather fresh stats. */
 355         d->value.playouts = 1;
 356         /* Correct color POV. */
 357         if (color == S_WHITE)
 358                 value.value = 1 - value.value;
 359
 360         /* We have three "value zones":
 361          * red zone | yellow zone | green zone
 362          *        ~45%           ~60%
 363          * red zone: reduce komi
 364          * yellow zone: do not touch komi
 365          * green zone: enlage komi.
 366          *
 367          * Also, at some point komi will be tuned in such way
 368          * that it will be in green zone but increasing it will
 369          * be unfeasible. Thus, we have a _ratchet_ - we will
 370          * remember the last komi that has put us into the
 371          * red zone, and not use it or go over it. We use the
 372          * ratchet only when giving extra komi, we always want
 373          * to try to reduce extra komi we take.
 374          *
 375          * TODO: Make the ratchet expire after a while. */
 376
 377         /* We use komi_by_color() first to normalize komi
 378          * additions/subtractions, then apply it again on
 379          * return value to restore original komi parity. */
 380         /* Positive extra_komi means that we are _giving_
 381          * komi (winning), negative extra_komi is _taking_
 382          * komi (losing). */
 383         floating_t extra_komi = komi_by_color(tree->extra_komi, color);
 384         int score_step_red = -a->score_step;
 385         int score_step_green = a->score_step;
 386
 387         if (a->score_step_byavg != 0) {
 388                 struct move_stats score = d->score;
 389                 /* Almost-reset tree->score to gather fresh stats. */
 390                 d->score.playouts = 1;
 391                 /* Correct color POV. */
 392                 if (color == S_WHITE)
 393                         score.value = - score.value;
 394                 if (score.value > 0)
 395                         score_step_green = round(score.value * a->score_step_byavg);
 396                 else
 397                         score_step_red = round(-score.value * a->score_step_byavg);
 398                 if (score_step_green < 0 || score_step_red > 0) {
 399                         /* The steps are in bad direction - keep still. */
 400                         return komi_by_color(extra_komi, color);
 401                 }
 402         }
 403
 404         /* Wear out the ratchet. */
 405         if (a->use_komi_ratchet && a->komi_ratchet_maxage > 0) {
 406                 a->komi_ratchet_age += value.playouts;
 407                 if (a->komi_ratchet_age > a->komi_ratchet_maxage) {
 408                         a->komi_ratchet = 1000;
 409                         a->komi_ratchet_age = 0;
 410                 }
 411         }
 412
 413         if (value.value < a->zone_red) {
 414                 /* Red zone. Take extra komi. */
 415                 if (DEBUGL(3))
 416                         fprintf(stderr, "[red] %f, step %d | komi ratchet %f age %d/%d -> %f\n",
 417                                 value.value, score_step_red, a->komi_ratchet, a->komi_ratchet_age, a->komi_ratchet_maxage, extra_komi);
 418                 if (a->losing_komi_ratchet || extra_komi > 0) {
 419                         a->komi_ratchet = extra_komi;
 420                         a->komi_ratchet_age = 0;
 421                 }
 422                 extra_komi += score_step_red;
 423                 return komi_by_color(extra_komi, color);
 424
 425         } else if (value.value < a->zone_green) {
 426                 /* Yellow zone, do nothing. */
 427                 return komi_by_color(extra_komi, color);
 428
 429         } else {
 430                 /* Green zone. Give extra komi. */
 431                 if (DEBUGL(3))
 432                         fprintf(stderr, "[green] %f, step %d | komi ratchet %f age %d/%d\n",
 433                                 value.value, score_step_green, a->komi_ratchet, a->komi_ratchet_age, a->komi_ratchet_maxage);
 434                 extra_komi += score_step_green;
 435                 if (a->use_komi_ratchet && extra_komi >= a->komi_ratchet)
 436                         extra_komi = a->komi_ratchet - 1;
 437                 return komi_by_color(extra_komi, color);
 438         }
 439 }
 440
 441 static floating_t
 442 bounded_komi(struct dynkomi_adaptive *a, struct board *b,
 443              enum stone color, floating_t komi, floating_t max_losing_komi)
 444 {
 445         /* At the end of game, disallow losing komi. */
 446         if (komi_by_color(komi, color) < 0
 447             && board_game_portion(a, b) > a->losing_komi_stop)
 448                 return 0;
 449
 450         /* Get lower bound on komi we take so that we don't underperform
 451          * too much. */
 452         floating_t min_komi = komi_by_color(- max_losing_komi, color);
 453
 454         if (komi_by_color(komi - min_komi, color) > 0)
 455                 return komi;
 456         else
 457                 return min_komi;
 458 }
 459
 460 static floating_t
 461 adaptive_permove(struct uct_dynkomi *d, struct board *b, struct tree *tree)
 462 {
 463         struct dynkomi_adaptive *a = d->data;
 464         enum stone color = stone_other(tree->root_color);
 465
 466         /* We do not use extra komi at the game end - we are not
 467          * to fool ourselves at this point. */
 468         if (a->no_komi_at_game_end && board_estimated_moves_left(b) <= MIN_MOVES_LEFT) {
 469                 tree->use_extra_komi = false;
 470                 return 0;
 471         }
 472
 473         if (DEBUGL(4))
 474                 fprintf(stderr, "m %d/%d ekomi %f permove %f/%d\n",
 475                         b->moves, a->lead_moves, tree->extra_komi,
 476                         d->score.value, d->score.playouts);
 477
 478         if (b->moves <= a->lead_moves)
 479                 return bounded_komi(a, b, color,
 480                                     board_effective_handicap(b, 7 /* XXX */),
 481                                     a->max_losing_komi);
 482
 483         floating_t komi = a->indicator(d, b, tree, color);
 484         if (DEBUGL(4))
 485                 fprintf(stderr, "dynkomi: %f -> %f\n", tree->extra_komi, komi);
 486         return bounded_komi(a, b, color, komi, a->max_losing_komi);
 487 }
 488
 489 static floating_t
 490 adaptive_persim(struct uct_dynkomi *d, struct board *b, struct tree *tree, struct tree_node *node)
 491 {
 492         return tree->extra_komi;
 493 }
 494
 495 struct uct_dynkomi *
 496 uct_dynkomi_init_adaptive(struct uct *u, char *arg, struct board *b)
 497 {
 498         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
 499         d->uct = u;
 500         d->permove = adaptive_permove;
 501         d->persim = adaptive_persim;
 502         d->done = generic_done;
 503
 504         struct dynkomi_adaptive *a = calloc2(1, sizeof(*a));
 505         d->data = a;
 506
 507         a->lead_moves = board_large(b) ? 20 : 4; // XXX
 508         a->max_losing_komi = 30;
 509         a->losing_komi_stop = 1.0f;
 510         a->no_komi_at_game_end = true;
 511         a->indicator = komi_by_value;
 512
 513         a->adapter = adapter_sigmoid;
 514         a->adapt_rate = -18;
 515         a->adapt_phase = 0.65;
 516         a->adapt_moves = 200;
 517         a->adapt_dir = -0.5;
 518
 519         a->zone_red = 0.45;
 520         a->zone_green = 0.50;
 521         a->score_step = 1;
 522         a->use_komi_ratchet = true;
 523         a->komi_ratchet_maxage = 0;
 524         a->komi_ratchet = 1000;
 525
 526         if (arg) {
 527                 char *optspec, *next = arg;
 528                 while (*next) {
 529                         optspec = next;
 530                         next += strcspn(next, ":");
 531                         if (*next) { *next++ = 0; } else { *next = 0; }
 532
 533                         char *optname = optspec;
 534                         char *optval = strchr(optspec, '=');
 535                         if (optval) *optval++ = 0;
 536
 537                         if (!strcasecmp(optname, "lead_moves") && optval) {
 538                                 /* Do not adjust komi adaptively for first
 539                                  * N moves. */
 540                                 a->lead_moves = atoi(optval);
 541                         } else if (!strcasecmp(optname, "max_losing_komi") && optval) {
 542                                 a->max_losing_komi = atof(optval);
 543                         } else if (!strcasecmp(optname, "losing_komi_stop") && optval) {
 544                                 a->losing_komi_stop = atof(optval);
 545                         } else if (!strcasecmp(optname, "no_komi_at_game_end")) {
 546                                 a->no_komi_at_game_end = !optval || atoi(optval);
 547                         } else if (!strcasecmp(optname, "indicator")) {
 548                                 /* Adaptatation indicator - how to decide
 549                                  * the adaptation rate and direction. */
 550                                 if (!strcasecmp(optval, "value")) {
 551                                         /* Winrate w/ komi so far. */
 552                                         a->indicator = komi_by_value;
 553                                 } else if (!strcasecmp(optval, "score")) {
 554                                         /* Expected score w/ current komi. */
 555                                         a->indicator = komi_by_score;
 556                                 } else {
 557                                         fprintf(stderr, "UCT: Invalid indicator %s\n", optval);
 558                                         exit(1);
 559                                 }
 560
 561                                 /* value indicator settings */
 562                         } else if (!strcasecmp(optname, "zone_red") && optval) {
 563                                 a->zone_red = atof(optval);
 564                         } else if (!strcasecmp(optname, "zone_green") && optval) {
 565                                 a->zone_green = atof(optval);
 566                         } else if (!strcasecmp(optname, "score_step") && optval) {
 567                                 a->score_step = atoi(optval);
 568                         } else if (!strcasecmp(optname, "score_step_byavg") && optval) {
 569                                 a->score_step_byavg = atof(optval);
 570                         } else if (!strcasecmp(optname, "use_komi_ratchet")) {
 571                                 a->use_komi_ratchet = !optval || atoi(optval);
 572                         } else if (!strcasecmp(optname, "losing_komi_ratchet")) {
 573                                 a->losing_komi_ratchet = !optval || atoi(optval);
 574                         } else if (!strcasecmp(optname, "komi_ratchet_age") && optval) {
 575                                 a->komi_ratchet_maxage = atoi(optval);
 576
 577                                 /* score indicator settings */
 578                         } else if (!strcasecmp(optname, "adapter") && optval) {
 579                                 /* Adaptatation method. */
 580                                 if (!strcasecmp(optval, "sigmoid")) {
 581                                         a->adapter = adapter_sigmoid;
 582                                 } else if (!strcasecmp(optval, "linear")) {
 583                                         a->adapter = adapter_linear;
 584                                 } else {
 585                                         fprintf(stderr, "UCT: Invalid adapter %s\n", optval);
 586                                         exit(1);
 587                                 }
 588                         } else if (!strcasecmp(optname, "adapt_base") && optval) {
 589                                 /* Adaptation base rate; see above. */
 590                                 a->adapt_base = atof(optval);
 591                         } else if (!strcasecmp(optname, "adapt_rate") && optval) {
 592                                 /* Adaptation slope; see above. */
 593                                 a->adapt_rate = atof(optval);
 594                         } else if (!strcasecmp(optname, "adapt_phase") && optval) {
 595                                 /* Adaptation phase shift; see above. */
 596                                 a->adapt_phase = atof(optval);
 597                         } else if (!strcasecmp(optname, "adapt_moves") && optval) {
 598                                 /* Adaptation move amount; see above. */
 599                                 a->adapt_moves = atoi(optval);
 600                         } else if (!strcasecmp(optname, "adapt_aport")) {
 601                                 a->adapt_aport = !optval || atoi(optval);
 602                         } else if (!strcasecmp(optname, "adapt_dir") && optval) {
 603                                 /* Adaptation direction vector; see above. */
 604                                 a->adapt_dir = atof(optval);
 605
 606                         } else {
 607                                 fprintf(stderr, "uct: Invalid dynkomi argument %s or missing value\n", optname);
 608                                 exit(1);
 609                         }
 610                 }
 611         }
 612
 613         return d;
 614 }