Received: from mail.nullprogram.com (mail.nullprogram.com [192.241.191.137]) by mail-b.sr.ht (Postfix) with ESMTPS id 2AF91FF080 for <~skeeto/public-inbox@lists.sr.ht>; Thu, 22 Oct 2020 03:05:38 +0000 (UTC) Received: from nullprogram.com (localhost [127.0.0.1]) by mail.nullprogram.com (Postfix) with ESMTPS id BA096C6F87; Wed, 21 Oct 2020 23:05:37 -0400 (EDT) Date: Wed, 21 Oct 2020 23:05:36 -0400 From: Christopher Wellons To: Eric Farmer Cc: ~skeeto/public-inbox@lists.sr.ht Subject: Re: I Solved British Square Message-ID: <20201022030536.uvnxjkw7skicj4f5@nullprogram.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) To help clarify, here's a scan of the original rules: https://images-na.ssl-images-amazon.com/images/I/81F-UCwOiYL._SX569_.jpg > but can he play there *after* the first turn (in which case presumably > the second player would have a winning strategy, since he can't > continue to mirror at that point)? Yes, the center rule only applies to the first player's first turn. The first player is free to play in the center on his second turn. The rule never applies to the second player. The ternary expression in my "valid()" function checks if it's the first turn and, if so, permits play anywhere except the center. On any other turn it consults the player's mask. If the first player plays one of the four tie openers, then the second player is blocked from the center by the adjacency rule. If the second player mirrors this move, then the first player is likewise locked out of the center. With the center off-limits to both players, the second player can always mirror and force a tie.