Tic-Tac-Toe Toss Tactics? (Posted on 2004-10-04)

	Submitted by Old Original Oskar!
Rating: 4.0000 (4 votes)
Solution:	(Hide)
If the first player starts in a corner (4/9 odds) and the second player doesn't answer in the center (7/8 odds), the first one will win; otherwise, it will be a draw. If the first player starts in the center (1/9 odds) and the second doesn't answer in a corner (4/8 odds) the first will win; otherwise, it will be a draw. Finally, if the first player starts in one of the four other possible squares (4/9 odds), if the second plays next to his (3/8 odds) or opposite (1/8 odds) it will be a draw; otherwise, the first player will win. Thus, the odds of the first player winning are 4/9x7/8 + 1/9x4/8 + 4/9x4/8 = 2/3, and the odds of a draw are 1/3. If a player goes first (1/2 odds) he will win with 2/3 odds, and tie with 1/3 odds. If he goes second (1/2 odds) he will tie with 1/3 odds, and lose with 2/3 odds. So, the odds of winning are 1/2x2/3=1/3; tying, 1/2x1/3+1/2x1/3=1/3, and losing, logically also 1/3.

	Subject	Author	Date
	Puzzle Thoughts	K Sengupta	2023-02-09 03:25:11
	I finally wrote my tic-tac-toe playing game	Penny	2004-10-27 11:37:39
	re(5): Solution	e.g.	2004-10-05 21:22:41
	re(4): Solution	Penny	2004-10-05 16:06:02
	re(3): Solution	Charlie	2004-10-05 13:46:37
	re(3): Solution	Charlie	2004-10-05 13:35:34
	re(2): Solution	Penny	2004-10-05 11:45:51
	re: Solution	Charlie	2004-10-05 09:52:21
	Solution	Penny	2004-10-05 09:06:49
	re: Here's a try	Federico Kereki	2004-10-04 12:41:13
	Here's a try	Rajal	2004-10-04 12:33:00