From 3610d97ab6e43ab798d18dd95f2d794377417160 Mon Sep 17 00:00:00 2001
From: Petr Baudis <pasky@ucw.cz>
Date: Wed, 23 Sep 2009 17:57:45 +0200
Subject: [PATCH] ucb1_prior(): Fix the anti-pass prior

---
 uct/policy/ucb1.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/uct/policy/ucb1.c b/uct/policy/ucb1.c
index 189a7cf..7a59342 100644
--- a/uct/policy/ucb1.c
+++ b/uct/policy/ucb1.c
@@ -99,10 +99,10 @@ ucb1_prior(struct uct_policy *p, struct tree *tree, struct tree_node *node, stru
 	struct ucb1_policy *pp = p->data;
 
 	if (is_pass(node->coord)) {
-		node->prior.playouts += 0;
-		node->prior.wins += 10;
-	}
-
+		/* Discourage passing */
+		node->prior.playouts += 10;
+		node->prior.wins += parity > 0 ? 0 : 10;
+	} else
 	/* Q_{even} */
 	/* This may be dubious for normal UCB1 but is essential for
 	 * reading stability of RAVE, it appears. */
-- 
2.11.4.GIT