WebSVN – Games.Chess Giants – Blame – //engine-crafty/resign.c

Rev	Author	Line No.	Line
33	pmbaty	1	#include "chess.h"
		2	#include "data.h"
154	pmbaty	3	/* last modified 08/03/16 */
33	pmbaty	4	/*
		5	*******************************************************************************
		6	* *
		7	* ResignOrDraw() is used to determine if the program should either resign *
		8	* or offer a draw. This decision is based on two criteria: (1) current *
		9	* search evaluation and (2) time remaining on opponent's clock. *
		10	* *
		11	* The evaluation returned by the last search must be less than the resign *
		12	* threshold to trigger the resign code, or else must be exactly equal to *
		13	* the draw score to trigger the draw code. *
		14	* *
		15	* The opponent must have enough time to be able to win or draw the game if *
		16	* it were played out as well. *
		17	* *
		18	*******************************************************************************
		19	*/
		20	void ResignOrDraw(TREE * RESTRICT tree, int value) {
108	pmbaty	21	int v, result = 0;
33	pmbaty	22
		23	/*
		24	************************************************************
		25	* *
		26	* If the game is a technical draw, where there are no *
		27	* pawns and material is balanced, then offer a draw. *
		28	* *
		29	************************************************************
		30	*/
		31	if (Drawn(tree, value) == 1)
		32	result = 2;
		33	/*
		34	************************************************************
		35	* *
		36	* First check to see if the increment is 2 seconds or *
		37	* more. If so, then the game is being played slowly *
		38	* enough that a draw offer or resignation is worth *
		39	* consideration. Otherwise, if the opponent has at least *
		40	* 30 seconds left, he can probably play the draw or win *
		41	* out. *
		42	* *
		43	* If the value is below the resignation threshold, then *
		44	* Crafty should resign and get on to the next game. Note *
		45	* that it is necessary to have a bad score for *
		46	* <resign_count> moves in a row before resigning. *
		47	* *
		48	* Note that we don't resign for "deep mates" since we do *
		49	* not know if the opponent actually saw that result. We *
		50	* play on until it becomes obvious he "sees it." *
		51	* *
		52	************************************************************
		53	*/
		54	if ((tc_increment > 200) \|\| (tc_time_remaining[Flip(root_wtm)] >= 3000)) {
		55	if (resign) {
		56	if (value < -(MATE - 15)) {
		57	if (++resign_counter >= resign_count)
		58	result = 1;
		59	} else if (value < -resign * 100 && value > -32000) {
		60	if (++resign_counter >= resign_count)
		61	result = 1;
		62	} else
		63	resign_counter = 0;
		64	}
		65	}
		66	/*
		67	************************************************************
		68	* *
		69	* If the value is almost equal to the draw score, then *
		70	* Crafty should offer the opponent a draw. Note that it *
		71	* is necessary that the draw score occur on exactly *
		72	* <draw_count> moves in a row before making the offer. *
		73	* Note also that the draw offer will be repeated every *
		74	* <draw_count> moves so setting this value too low can *
		75	* make the program behave "obnoxiously." *
		76	* *
		77	************************************************************
		78	*/
		79	if ((tc_increment > 200) \|\| (tc_time_remaining[Flip(root_wtm)] >= 3000)) {
		80	if (Abs(Abs(value) - Abs(DrawScore(game_wtm))) < 2 &&
		81	moves_out_of_book > 3) {
		82	if (++draw_counter >= draw_count) {
		83	draw_counter = 0;
		84	result = 2;
		85	}
		86	} else
		87	draw_counter = 0;
		88	}
		89	/*
		90	************************************************************
		91	* *
		92	* Now print the draw offer or resignation if appropriate *
		93	* but be sure and do it in a form that ICC/FICS will *
		94	* understand if the "xboard" flag is set. *
		95	* *
		96	* Note that we also use the "speak" facility to verbally *
		97	* offer draws or resign if the "speech" variable has been *
		98	* set to 1 by entering "speech on". *
		99	* *
		100	************************************************************
		101	*/
		102	if (result == 1) {
		103	learn_value = (crafty_is_white) ? -300 : 300;
		104	LearnBook();
		105	if (xboard)
		106	Print(4095, "resign\n");
		107	if (audible_alarm)
		108	printf("%c", audible_alarm);
		109	if (speech) {
		110	char announce[128];
		111
108	pmbaty	112	strcpy(announce, "./speak ");
		113	strcat(announce, "Resign");
		114	v = system(announce);
		115	if (v <= 0)
		116	perror("ResignOrDraw() system() error: ");
33	pmbaty	117	}
		118	if (crafty_is_white) {
		119	Print(4095, "0-1 {White resigns}\n");
108	pmbaty	120	strcpy(pgn_result, "0-1");
33	pmbaty	121	} else {
		122	Print(4095, "1-0 {Black resigns}\n");
108	pmbaty	123	strcpy(pgn_result, "1-0");
33	pmbaty	124	}
		125	}
		126	if (offer_draws && result == 2) {
		127	draw_offered = 1;
		128	if (!xboard) {
108	pmbaty	129	Print(1, "\nI offer a draw.\n\n");
33	pmbaty	130	if (audible_alarm)
		131	printf("%c", audible_alarm);
		132	if (speech) {
		133	char announce[128];
		134
108	pmbaty	135	strcpy(announce, "./speak ");
		136	strcat(announce, "Drawoffer");
		137	v = system(announce);
		138	if (v <= 0)
		139	perror("ResignOrDraw() system() error: ");
33	pmbaty	140	}
		141	} else if (xboard)
		142	Print(4095, "offer draw\n");
		143	else
		144	Print(4095, "\n*draw\n");
		145	} else
		146	draw_offered = 0;
		147	}

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Games.Chess Giants//engine-crafty/resign.c – Rev 154