Test of photo resizing



HaChu on a new machine

For some weeks now, the 5 HaChu bots running on 81dojo are powered by a new machine. This is an Intel® Core™ i7-4770K CPU @ 3.50GHz × 8 (that’s 4 cores, each hyperthreaded), with 32 GB memory, running Linux Fedora 20. This should give the bot at least twice as much power compared with before, when it was running on a laptop. This should result in slightly longer look-ahead, and therefore stronger tactical power.

Continuation from White’s counter-foray

The last post in this mini-series on the opening resulting from Black’s early Lion foray, showed White retaliating in kind in response to Black supporting the Lion with the Go-Between. The position was this:

Black plays GB - 9g and White responds with his own Lion foray

Black plays GB – 9g and White responds with his own Lion foray

Black’s intention in supporting the Lion with the Go-Between is to follow up with a “sacrifice” of the Dragon Horse. To this end he first plays P – 5h, Ln x 4h – 4g, then plays DH x 10+, yielding this position:

Black proceeds to "sacrifice" the Dragon Horse

Black proceeds to “sacrifice” the Dragon Horse

Since the Horned Falcon now threatens to “eat” the Rook on 10c without moving, White has no choice but to capture it, so taking with the Rook is clearly best. Black then captures the Rook with the Bishop. The exchange of Dragon Horse for Rook and Pawn is about even, but the promotion of the Bishop gives Black perhaps a slight edge in material. Additionally,  his Lion is still supported in an attacking position. Therefore White does best to retaliate in kind, leading to this position:

Position after exchange and White retaliates.

Position after exchange and White retaliates.

Now the position is almost symmetrical, the only differences being that Black has advanced his Go-Between to support the Lion, and White has played the developing move of P – 5e, opening a diagonal. If Black were to now also open the diagonal with P – 8h, White would have a chance to make it completely symmetrical with GB – 4f, but why would he choose such a slow, non-developing move, when there is no need to protect his Lion? So I conclude that Black has wasted the advantage of the first move. Extensive experience in this position confirms that Black seems unable to get an advantage in this position.

The series will continue by examining the better alternative to GB – 9g, namely retreating the Lion to 7h.

Getting used to playing against HaChu 0.19

The human results are getting better. White_horse is beating it most of the time. Kenjin has beaten it a couple of times.

H.G.Muller (Test_DontPlayMe), the author of HaChu, observed that it doesn’t see the danger of piece pile-ups when it is pinned. Inspired by this, last night I decided to play it on evens, despite not yet having beaten it with 2 Kings.

I played straight-forwardly, without a special strategy. As soon as it brought it’s Lion out into the centre, a fight broke out. I concentrated on pinning its pieces against the lion and ganging up on them. This way I acquired a small material advantage. The centre fight continued and my advantage increased until I got a second Lion. Then the programmed stupidity kicked in during the endgame, and I had an easy finish.