Author: Uri Blass
Date: 03:38:48 10/01/00
Go up one level in this thread
On October 01, 2000 at 05:14:42, Mike Adams wrote: >On October 01, 2000 at 04:48:41, Uri Blass wrote: > >>On October 01, 2000 at 04:20:46, Mike Adams wrote: >> >>> I've noticed that pulsar thinks the doubled pawns are worth more than the >>>danger of exposing its castle. When its white and castles kingside this is >>>particular dangerous when it opens the H file especially if the rook is sitting >>>right there on H8. I'm not as concerned about the F and G files because I think >>>it can better defend these files but it can be very difficult to moblize the >>>pieces to defend the H file. Should i put a penalty in at 1.5 times the doubled >>>pawn bonus? >> >>Chess is not a simple game. >>There are cases when open h file is not dangerous inspite of castling in the >>king side and there are cases when open f file is dangerous. >> >>I think that it is impossible to answer your question because the right panelty >>for open file should be dependent in the rest of the evaluation. >> >>Uri > >yes but take a look at this position. pulsar is black and it plays Nxg3. > >[D] r1bq1rk1/ppp2p2/2n4p/3pP1pn/3P4/2P2NB1/P1P1B1PP/R2QK2R b KQ - 0 14 > > >I think there are some general rules that you dont open the H file with the >opponents rook on H8. Pulsar does have a king saftey function that tells it not >to advance its castle side pawns but in some positions it seems to like doing >that. Maybe i'm not doing it right i gave it penalties similar to what the >simple chess program does for advancing castled pawns but sometimes when it >advances one pawn I think it gets easier for it to advance another if it thinks >it messes with the opponents postion. That is another area i'll have to look >at. With a check extension and deeper search pulsar, now over 2250 icc blitz, >can get itself out of a lot of diffictulties but some things are just stupid and >in this case i need to build into the evaluate that NxG3 followed by G4 are >really bad. The question is how to do that in a narrow sense that does not give >it rules that are bad half the time. >The move sequence of the game was: .. NxG3 HxG3 G4 Qg2 Gxf3 Qxh6 and of course >its over. Getting it to see Gxf3 is bad is not easy to do. the material value >of the Knight distorts the search and particulary with nullmove its hard to see >at shallower depths like 5 or 6 even with check extensions. I'm trying the >positon at Gxf3 on different versions of pulsar to see how much depth it takes >to see that. So far with NUll move off it does the best and sees it at depth 6. >A freind said he tried it with crafty and crafty had a hard time seeing that >Gxf3 is bad but I did not get to see that for myself. Crafty17.11 on a slow pentium200 has no problem to see in 3 seconds that gxf3 is losing. Crafty17.11 has also no problem to see after 68 seconds with the same hardware that the position after g4 Qd2 is bad for black(the score is 4.40 pawns for white at depth 9 for the move h5. The tactical mistake is g4 and there is no reason to push the pawns forward. I do not think that Nxg3 is a good idea but after Nxg3 hxg3 Kg7 I do not see a clear win for white. Uri
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