So after a small tweak, it actually plays well!

1 files changed, 6 insertions, 4 deletions

diff --git a/include/ct1986.c b/include/ct1986.c
index 706640e..8378f8c 100644
--- a/include/ct1986.c
+++ b/include/ct1986.c
@@ -4,6 +4,7 @@
 // Globals
 // ===================================================================
 
+const float infty = 3.0;
 char ct1986_ptn[9];
 void (*ct1986_display_progress)(const uint8_t);
 
@@ -121,16 +122,17 @@ previous_ply(void) {
 		if ((min == 0) && (w == WIN_ROAD_BLACK \
 											 || w == WIN_FLAT_BLACK \
 											 || w == WIN_DRAGON)) { \
-			this = +3; \
+			this = infty; \
 		} else if ((min > 0) \
 							 && (w == WIN_ROAD_WHITE \
 									 || w == WIN_FLAT_WHITE \
 									 || w == WIN_DRAGON)) { \
-			this = -3; \
+			this = -infty; \
 		}	/* Otherwise decide what to do based on our depth  */ \
 	} else if (cur_depth == max_depth) { \
 		/* We're at the bottom, evaluate */ \
 		this = ct1986_evaluate_black_win(); \
+		if (min == 0) this = this - 1.0;\
 	} else { \
 		/* We're not at the bottom, recurse first */ \
 		next_ply(); \
@@ -160,7 +162,7 @@ ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
 		black_count_backup = black_count;
 
 	// 1.0 is a `certain' black win, -1.0 is a `certain' white win.
-	float this = 0, optimal = (min) ? 2.0 : -2.0;
+	float this = 0, optimal = (min) ? infty : -infty;
 
 	// Step across the board
 	for (uint8_t row = 0; row < board_size; row++) {
@@ -269,5 +271,5 @@ ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
 
 inline float
 ct1986_generate(const uint8_t max_depth) {
-	return ct1986_minimax(0, max_depth, 0, -10, 10);
+	return ct1986_minimax(0, max_depth, (ply & 1) ? 0 : 1, -infty, infty);
 }