Author: Robert Hyatt
Date: 14:17:26 09/22/01
Go up one level in this thread
On September 22, 2001 at 12:40:57, Miguel A. Ballicora wrote: >On September 22, 2001 at 09:57:10, Robert Hyatt wrote: > >>On September 22, 2001 at 01:39:15, Miguel A. Ballicora wrote: >> >>>On September 22, 2001 at 00:52:06, Robert Hyatt wrote: >>> >>>>On September 22, 2001 at 00:43:03, Robert Hyatt wrote: >>>> >>>>>On September 21, 2001 at 23:45:54, Miguel A. Ballicora wrote: >>>>> >>>>>>On September 21, 2001 at 23:01:29, Robert Hyatt wrote: >>>>>> >>>>>>>On September 21, 2001 at 17:01:35, Miguel A. Ballicora wrote: >>>>>>> >>>>>>>>On September 21, 2001 at 16:45:44, Robert Hyatt wrote: >>>>>>>> >>>>>>>>>On September 21, 2001 at 16:27:01, Gian-Carlo Pascutto wrote: >>>>>>>>> >>>>>>>>>>On September 21, 2001 at 14:57:20, Robert Hyatt wrote: >>>>>>>>>> >>>>>>>>>>>I don't mind that kind of mis-evaluation so much. If anybody wins, white >>>>>>>>>>>wins. What I would not like is to see that kind of evaluation and then lose >>>>>>>>>>>the game... >>>>>>>>>> >>>>>>>>>>The problem is when crafty prefers the 1.8 from this ending over the 1.7 from >>>>>>>>>>another ending that _is_ won for white. >>>>>>>>>> >>>>>>>>>>That'll cost you half a point. >>>>>>>>>> >>>>>>>>>>-- >>>>>>>>>>GCP >>>>>>>>> >>>>>>>>> >>>>>>>>>I don't disagree. But it is just as important to not lose when you can win >>>>>>>>>or draw. The not drawing when you can win is another level of tuning. I need >>>>>>>>>to study the ending because a pawn on the a and c file becomes very hard for >>>>>>>>>a lone king to stop... it might have simply made a mistake and drawn a won >>>>>>>>>position in this case.. I didn't look at it very carefully (yet). >>>>>>>> >>>>>>>>It looks drawn. As you already know, the advantage of the outside passer is that >>>>>>>>you can sacrifice it and the king can go and eat up the opponent pawns on the >>>>>>>>other side. In this case it is impossible (that's the problem here). For >>>>>>>>instance, place the pawns in g6,h5,g4. How can the white king capture them? it >>>>>>>>can't because as soon as you capture g6 black plays h4 and promotes. On the >>>>>>>>other hand, two passers cannot beat a king on the Q side, they need the help of >>>>>>>>the wKing. however, the wK cannot go to the Q side because black promotes. >>>>>>>> >>>>>>>>Regards, >>>>>>>>Miguel >>>>>>> >>>>>>> >>>>>>>I don't believe it is quite that simple. If the pawns are zugged on the >>>>>>>kingside, the two passers on the queenside can easily win. This is the >>>>>>>attraction of "wild 7" on ICC, which is what the "mini game" is all about. >>>>>> >>>>>>I am not sure what you mean by zugged pawns. Anyway, white cannot capture the >>>>>>pawns in any case, so how can white win? two passers, if they are not separated >>>>>>enough, cannot win without king support. >>>>>>The only chance is a race, when white king rush to the Q side to support them >>>>>>letting a black pawn to promote. >>>>>> >>>>>> >>>>>>>In this zug-less position (at present) things aren't so clear, of course, >>>>>>>but >>>>>>>put the black pawns at g5 and h6 and the white pawn at g4, and this turns >>>>>>>into a simple white win... >>>>>> >>>>>>Black plays h5 and it is a draw. I think I did not understand. >>>>>> >>>>>>Regards, >>>>>>Miguel >>>>> >>>>> >>>>>You are assuming that a KQ vs KQPP is a draw? IE after h5, I play gxh5 and I >>>>>promote first. >>> >>>But I play g6xh5 first and you don't promote ;-) >>>I think we are talking about different things. You are setting a position >>>with only h6 and g5? then I have pawn less and has little to do with the game >>>itself. >>> >> >> >>OK... let's back up a bit. >> >>I have an a and c pawn, and a pawn at g5. You have pawns at g6/h7. That is >>the position in the game under discussion. Crafty was up a pawn, and had an >>eval of +2.something, although the game was later drawn. >> >>I am going to use my king to advance my a/c pawns. If you leave that >>area, I will promote easily. If you play h6, I am going to play gh and >>promote on the h file if your king isn't close enough, or on the a file if >>you try to stop the h pawn. > >This position has nothing to do with the game. I believe you are trying >to make a point, but I do not see it. > The position is related to the game because of the following: White has three pawns, black has two. White has the passed a and c pawns, but black's pawns are immobilized. I don't think it is easy to evaluate this game as won, lost or drawn, just by looking at material, or anything else. It is very complex... >>That was the reason for setting up the kingside pawns so that you don't have >>any moves over there. With my queen-side pawns at (say) c4/a4 I don't see how >>your king is going to stop them. Wheneven you approach one, the other advances. >>If you "wait" I wait also by advancing my king. > >You can never promote with a and c pawns without king support unless they find >a way to reach the 6th rank safely. Even if you can wait with your king. If you >cannot wait with your king is even worse, you lose. (in fact, you even lose with >three pawns a, b and c). > >[D]8/8/1k6/8/P1P5/7P/6Pp/6K1 w - - > >this is a draw. Even with the bKing in b7 or b8. > >Regards, >Miguel Not quite. Because the black king can't abandon the two white pawns. Nor can it attack them. So the black king is fixed. If the white king gets to the black pawns quickly enough, white wins easily. That was the problem with this position, from crafty's perspective... > >>This was why I said it doesn't seem so easy to try to statically evaluate >>this, although I think I have some ideas of how to do this a bit more >>accurately by fixing what looks like a bug.
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