Author: Rolf Tueschen
Date: 16:26:32 01/21/03
Go up one level in this thread
On January 21, 2003 at 19:03:16, Robert Hyatt wrote: >On January 21, 2003 at 17:19:53, Rolf Tueschen wrote: > >>On January 21, 2003 at 16:16:19, Robert Hyatt wrote: >> >>>On January 21, 2003 at 15:25:21, Rolf Tueschen wrote: >>> >>>>On January 21, 2003 at 14:35:50, Robert Hyatt wrote: >>>> >>>>>On January 21, 2003 at 09:17:36, Rolf Tueschen wrote: >>>>> >>>>>>On January 21, 2003 at 09:09:49, Ricardo Gibert wrote: >>>>>> >>>>>>>On January 21, 2003 at 08:52:02, Rolf Tueschen wrote: >>>>>>> >>>>>>>>On January 20, 2003 at 23:00:55, Ricardo Gibert wrote: >>>>>>>> >>>>>>>>>On January 20, 2003 at 21:57:38, Robert Hyatt wrote: >>>>>>>>> >>>>>>>>>>On January 20, 2003 at 21:32:22, Ricardo Gibert wrote: >>>>>>>>>> >>>>>>>>>>>On January 20, 2003 at 20:44:21, Robert Hyatt wrote: >>>>>>>>>>> >>>>>>>>> >>>>>>>>>[snip] >>>>>>>>> >>>>>>>>>>>>Round 6 Crafty vs Searcher >>>>>>>>>>>> >>>>>>>>>>>>A near disaster for the first game of the second day. The same d4 opening >>>>>>>>>>>>led to a similar position, but things did not go very well here. First score >>>>>>>>>>>>out of book was -.42, which was typical for every 1. d4 game crafty played as >>>>>>>>>>>>white. But it was able to pull that up quickly normally. 10 moves out of book, >>>>>>>>>>>>the score hadn't changed, showing that searcher was playing very well and with >>>>>>>>>>>>a reasonable amount of understanding of the position. >>>>>>>>>>>> >>>>>>>>>>>>Finally by move 24, Crafty was back to a slightly + score, and this held until >>>>>>>>>>>>it started dropping as it misjudged the queen/rook attacking in the center. At >>>>>>>>>>>>move 32, the score was -.68 after 16 plies. at move 35, the score was -1.5, at >>>>>>>>>>>>move 40 -2.0, -2.5 at move 50, -3 at move 60, and at this point Crafty dug >>>>>>>>>>>>in its heels and pulled the score back to -2.3 where it stayed for a long >>>>>>>>>>>>while. But it slowly traded pawns, and the score started swinting back. By >>>>>>>>>>>>move 80, it was -2.0 again, -1.5 by move 85, -1.0 by move 95, and it finally >>>>>>>>>>>>reported a draw score at move 102. Of all the games it played, this was a >>>>>>>>>>>>really nice effort as it showed a lot of understanding about king rook and pawn >>>>>>>>>>>>endings, something I have worked on a lot over the years. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>I find your last sentence surprising. Crafty was very lucky in this game that >>>>>>>>>>>Searcherx did not play 62...Re8 62.Kxg3 Rb8 winning easily. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>>Crafty says if you play Re8 it just plays Rb7 immediately, not Kg3. >>>>>>>>>> >>>>>>>>>>Score doesn't change much... >>>>>>>>>> >>>>>>>>>>It may be overlooking something, but it isn't going to let black get >>>>>>>>>>the rook behind the pawn... >>>>>>>>>> >>>>>>>>>>Maybe we are at the wrong move? IE you have two move 62's above. >>>>>>>>>>Do you mean 61. Re8? >>>>>>>>> >>>>>>>>> >>>>>>>>>Yes. 61...Re8 62.Kxg3 Rb8 was my intention. >>>>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>>Going back to move 61, and playing Re8 Kg3 Rb8 I get Rd4 and Rb4. White >>>>>>>>>>loses one of the pawns on the h file, but only one. It isn't clear to me, >>>>>>>>>>without a lot of study, how black makes progress. The pawn is blockaded, so >>>>>>>>>>the black rook is stuck on the b file unless it gives check. The black >>>>>>>>>>king can't abandon the kingside or white will eat the g pawn and the hpawn >>>>>>>>>>should be enough to force the trade of the rook and a draw... >>>>>>>>> >>>>>>>>>[D]8/1p1R2pk/5p2/7P/7P/5Kn1/4r3/8 b - - 0 60 >>>>>>>>> >>>>>>>>>61...Re8 62.Kxg3 Rb8 63.Rd4 b5 64.Rb4 Kh6 65.Kg4 Rb7 66.Kh3 Kxh5 67.Kg3 g6 >>>>>>>>>68.Kh3 f5 69.Kg3 Rb6 70.Kh3 Rc6 71.Rb3 Rc4 is a prosaic and convincing win. >>>>>>>> >>>>>>>>A comparable position is available with many different continuations. One is >>>>>>>>your 61-Re8 others I pointed out in >>>>>>>>http://www.talkchess.com/forums/1/message.html?278466 >>>>>>>>The point is that you always winn with the f/g free pawns if they are so good >>>>>>>>combined. No need to know the rule of the R behind the pawns because you give >>>>>>>>the b pawn away. >>>>>>>> >>>>>>>>Kind regards, >>>>>>>>Rolf Tueschen >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>>Even though it is later given away, it handcuffs the defense giving time to make >>>>>>>preparations before giving up the b-pawn to win on the K-side, so it is still an >>>>>>>important tool. >>>>>> >>>>>>No doubt about it. But I was looking for the programmers and you said yourself >>>>>>that this is difficult to program. So I had a look at totally normal chess, >>>>>>calculable or countable if you like. And this position with the combined pawns >>>>>>is won and that is the whole thing. I meant the argument of the "difficult" >>>>>>Re8-b8 is even not necessary. >>>>>> >>>>>>Rolf Tueschen >>>>>> >>>>>> >>>>> >>>>>One of the problems here is that the f and g pawns are _not_ passed. The f pawn >>>>>is. The >>>>>g-pawn is not, because white hangs on to the h-pawn. Here are the problems I >>>>>see that have >>>>>to be solved: >>>>> >>>>>1. black's rook is behind the b-pawn. If black moves the rook without giving >>>>>check, the >>>>>pawn goes away as it is attacked by white's rook. >>>>> >>>>>2. I will assume the h5 pawn is going to "go". After Re8 Kxg3 Rb8 Rd4 b5 Rb4 >>>>>the rooks >>>>>are stuck. Black can move to b8/b7/b6. White can't move the rook or the pawn >>>>>advances. >>>>> >>>>>3. After black takes on h5 and white keeps the king at g3-h3 to hold the >>>>>h-pawn, black has >>>>>a couple of plans. But not all work. The king can't go help the rook, because >>>>>white's king makes >>>>>that a long path and it is close to the kingside pawns. the king can't win the >>>>>white h-pawn by >>>>>itself, and it can't get the rook up to attack it. So either the king goes to >>>>>the queenside to help >>>>>the b-pawn advance, or black tries advancing the f-pawn. >>>>> >>>>>White definitely has many problems here, but the question is "are they _all_ >>>>>unsolvable?" >>>>>It isn't that clear to me. One thing is for sure, it isn't an "easy win". It >>>>>is going to take a lot >>>>>of sweat and calculation. >>>> >>>>Sorry, Bob, you must have been tricked by your own program because GR is right, >>>>this is really easy. Just play through his variation. You as White have no >>>>chance to deviate from that line more or less. The plan of Black is so easy: >>>>Your R is on b4, then he puts his R on b6 and when it suits him he will go for >>>>the double attack on your last pawn h4. So the b pawn has no meaning after all. >>>>It is just to keep you in tension with your R. Then, when the last pawn of White >>>>has been taken, the rest is known theory. And you can't do anything against it. >>>>So - what I found very clever during the game, that Crafty played merry-go-round >>>>in the center with R and N and for all neutralized the dangerous d pawn, that >>>>does not draw because of the given final. And Black could win earlier, with my >>>>move Rf2 instead Rc3, and your K is outplaced. So you must search for >>>>alternatives way earlier. The structure with the double pawn is weak. First the >>>>d pawn and then Black also had the free b pawn afterwards, so basically it's not >>>>the good game by Crafty as I had thought at first. But overall you were very >>>>good with Ferret who normally should draw in the last round and then tie with >>>>you. Ferret played really sharp chess while you are extremely good in your time >>>>management, that was very obvious to me. Was one of the best results for you, >>>>right? >>>> >>>>Rolf Tueschen >>>> >>>> >>>> >>> >>>No. The ferret result was _bad_. A loss is bad. :) >>> >>>the ruffian and yace games were good. They were wins. :) >>> >>>However, until I have time to study the searcher endgame, I can't say much more. >>>It isn't an "easy" win in my opinion (by black). It might be winnable. But >>>there >>>are enough places to go wrong that a human might well have problems. IE it >>>would be interesting to play this against a human at a minute a move or whatever >>>to see how "easy" it turns out to be. :) >>> >>>I would expect more than one "oh shit!" during the experiment. :) >>> >>>Humans might think that they know all about rook endings. But if you go back >>>prior >>>to endgame tables, humans thought they knew all about KQ vs KR, until belle >>>showed >>>the world that the king and rook to _not_ stay together for best defense. >>> >>>So while I don't like white's position, until I study it in detail, I haven't >>>concluded it >>>is lost yet, myself... >> >> >>PROPOSAL: >> >>As Ricardo said he is now sure how to win against all defense. Bob, couldn't we >>organize that on ICC on a specific date so that many of us could follow? >>Ricardo, would that be possibl for you to go on ICC? >> >>Rolf Tueschen >> > >I can do that... > >Bob > >Note that I have not said that black can't win. I have said "I don't see >an absolutely forced win _yet_ although I have not spent more than a couple >of minutes looking at it. > >But it would be an interesting test to do... Yes, and as I remember you did the like with GM Roman all along in the past. But it would be fun to watch in such ambiance as ICC on Sunday perhaps with comments? By some master? I think such sessions would also be very educative for both fans and experts in CC. Your analogy with KR-KQ was not so good because here in the game Black HAS a clear strategy while in the classic experiment it's much more difficult even for Worldchampios because a human player can't handle 30 or 40 move (often only-moves) lines without having a real clue of what is going on, so it's a terrible task of calculations. While for the machine it's just playing +45. Here you have not much choice, strategically. Let me add another lay idea. Could you comment? I think it is of big importance to tell the engine which 'complex' - if all other items have gone - is a clear win. For instance here the two pawns. Of course the engine should be able to win it. Otherwise it could be better to let it play for its own ideas. So if you win with the two pawns and R-R, you might understand that the dangerously looking b-pawn could even be sacced. Although normally you think that material is important. Is it possible to code such details? Because it would come closer to the cluster thinking. Another question: is it possible to program such things as the analysis of much later situations, but hereby to be able to judge the real situation of the actual position? Let's go back to earlier situations. If you have that sort of code, it might be resulting in a closer similarity to GM chess because you begin to think about possibilities to either omit or create _later_ possible clusters. Is that of help or is it impossible out of principal reasons? For instance that you can't leave the time axis. I don't know what else. Rolf Tueschen > > >> >> >>> >>> >>>>>>> >>>>>>>[snip]
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