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Subject: Re: h5 with many of the old 1997 comments are interesting

Author: Gerd Isenberg

Date: 13:43:33 09/29/05

Go up one level in this thread


On September 29, 2005 at 15:33:43, Robert Hyatt wrote:

>On September 29, 2005 at 13:53:27, Gerd Isenberg wrote:
>
>>[D] r2qk2r/pp3ppp/2p1pn2/4n3/1b6/3P2PP/PPPN1PB1/R1BQK2R b KQkq - 4 1
>>>>11...h5 is very logical for computer to play.
>>>>It increase the mobility of the rook at h8 so there is no reason for computers
>>>>not to play it.
>>>
>>>Sorry, but I _totally_ disagree there.  Most any decent computer chess program
>>>has an evaluation component that covers the king-side pawn structure.  Playing
>>>h5 creates a pawn target for black to aim at.  It weakens g5 and g6.  So a
>>>computer has to see something _else_ to more than offset that king safety issue.
>>>
>>
>>Seems that Fruit doesn't care so much about pushing pawns on one wing, if the
>>own king has still the option to castle to the other sheltered wing without
>>enemy pawn advances there.
>>
>>The move is somehow committing and narrows black options to castle (kingside
>>here)  - but also, or even more, white castle options.
>>
>>
>>>I suspect _many_ strong computers will _not_ play this move, for the reason
>>>given above, since any long-term gain by the move is way beyond any search
>>>horizon, and is going to be purely based on positional scoring numbers..
>>>
>>>Mobility of the rook is a lousy reason for h5.  Otherwise black would always be
>>>playing a5 and h5 to give both rooks more mobility...
>>>
>>
>>Agreed - but for the same reason, black king still has a nice shelter on the
>>queenside and may castle queenside, rook mobility might be an issue here.
>>
>>Gerd
>
>
>Would seem to me that white has that same "castle queenside" option open,
>although it will take a couple of moves to prepare by getting development done
>over there...
>
>Crafty has that same sort of "it is ok to disrupt pawns on one side if castling
>to the other side is still an option, but it also used to have an anti-opposite
>castling term to avoid very precise lines where it would have a chance to lose
>one tempo and the game quickly after that...
>
>Still won't play h5, even the new non-asymmetric version that is being developed
>right now...


Fruit's initial found of h5 might be a "wrong" reason case, but the later pvs
indicate that 0-0 is "difficult" for both sides (probably due to pawn shelter or
pawn storm issues), and that black castles queen side with the white king still
in center:

00:00:02.5	0.04	10	2475965	O-O O-O Nd5 Re1 Qc7 Qe2 Ng6 c3 Bc5 Nc4
00:00:04.2	0.11	10	4088578	h5 a3 Bd6 Ne4 Nxe4 Bxe4 f5 Bg2 Bc5 Bd2 Kf7
00:00:07.8	0.11	11	7518463	h5 Qe2 Bd6 f4 Ng6 Nc4 h4 f5 Bxg3+ Kd1 Nf8 Bd2
00:00:19.3	0.00	12	18830729	h5 O-O h4 d4 Qxd4 c3 Qb6 cxb4 hxg3 Qb3 gxf2+ Rxf2
Qd4 b5
00:00:41.3	-0.05	13	40615296	h5 O-O h4 d4 Qxd4 c3 Qb6 cxb4 hxg3 Qe2 Ned7 Nc4
gxf2+ Rxf2 Qxb4
00:02:17.0	0.00	14	133102696	h5 Qe2 Qc7 O-O h4 Ne4 Be7 Be3 Nd5 d4 Nxe3 fxe3 Nd7
Qf2 O-O gxh4
00:05:17.0	0.08	15	307648549	h5 Qe2 Qc7 c3 Be7 Ne4 h4 Nxf6+ Bxf6 g4 Ng6 Be4 Nf4
Bxf4 Qxf4 d4 O-O O-O
00:10:54.5	0.07	16	633368278	h5 Qe2 Qc7 c3 Be7 Ne4 h4 Nxf6+ Bxf6 g4 O-O-O d4 Ng6
Be4 Nf4 Bxf4 Qxf4 Qe3 Bg5
00:16:44.6	-0.02	17	977058195	h5 Qe2 Qc7 c3 Be7 h4 O-O-O d4 Neg4 Nc4 Nd5 O-O Bf6
f3 Nh6 Bxh6 Rxh6 f4
00:42:35.1	-0.02	18	-1805878841	h5 Qe2 Qc7 c3 Be7 h4 O-O-O d4 Neg4 Nc4 Nd5 O-O
Bf6 a4 Kb8 Re1 Be7 Be4
01:17:57.7	-0.06	19	267945229	h5 Qe2 Qc7 c3 Be7 h4 O-O-O d4 Neg4 Nc4 Nd5 O-O Bf6
Re1 g6 Bf3 Kb8 Bd2 c5 Bxg4 hxg4 dxc5 Qxc5 Qxg4




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