engines & positional play

[GenoM]

Do you remember Kasparov' words: "Positionally Hiarcs is better than Deep Blue"?

[Dr.Wael Deeb]

Hiarcs 8 Bareev is rated 2632 Elo in my rating list and as far as I am concerned is the most positional engine I've ever tested

[ArmyBridge]

I think that all top engine could play positionally on decent way, without any serious mistake, the main weak is that in certain position where you must wait or you must start to play more smooth the programm can´t wait and begin to ruin their position being too ambitious...mmm well maybe Rybka usually waits for, if it does not see clear advantage it hold the position in almost a intelligent way, Fritz 11 tends to play like Rybka. I guess that we can divide to the programs in 2 categories those that tend to tactics and those that have solid play. In the first cat. we can put: Junior (of course) Fritz 9 and Fritz 10, Spike, Glaurung, Toga, Gambit Tiger
and in the second cat. we have Rybka Fritz 11, Shredder 11, Naum, other engines rolle in 1 and 2 cat. like Fruit, Hiarcs (is has a very positional play, but when it see a chance would play very tactics) Loop and Zappa. For me the most positional engine is Fritz 11,it is a very complete program in the 3 phases of the game, shredder plays the end extraordinarily well, Rybka bases its force on the midle game but it plays some end´s very bad. Naum is a rock, very very solid an punish the most little mistake.
Have a nice day

[Graham Banks]

I looked for examples four or so years ago and couldn't find any.

I asked for some help on the Rybka forum and Vas replied:

Graham,

I definitely agree with your comment. For some ancient examples, take a look here:

http://www.rybkachess.com/index.php?aus ... hange+sacs
http://www.rybkachess.com/index.php?aus ... sacrifices

Newer Rybka versions are even much better at this.

Vas

[smirobth]

I looked for examples four or so years ago and couldn't find any.

I asked for some help on the Rybka forum and Vas replied:

Graham,

I definitely agree with your comment. For some ancient examples, take a look here:

http://www.rybkachess.com/index.php?aus ... hange+sacs
http://www.rybkachess.com/index.php?aus ... sacrifices

Newer Rybka versions are even much better at this.

Vas

Thanks Graham. However in the first link you provided every single exchange sac involved not only positional compensation, but also at least one pawn for additional compensation and sometimes two pawns (which is no sac at all). And the second link shows only pawn sacs, not exchange sacs. So these links are making my case for me .... programs don't seem to sac a full exchange for purely positional compensation.

[Dann Corbit]

I looked for examples four or so years ago and couldn't find any.

I asked for some help on the Rybka forum and Vas replied:

Graham,

I definitely agree with your comment. For some ancient examples, take a look here:

http://www.rybkachess.com/index.php?aus ... hange+sacs
http://www.rybkachess.com/index.php?aus ... sacrifices

Newer Rybka versions are even much better at this.

Vas

Thanks Graham. However in the first link you provided every single exchange sac involved not only positional compensation, but also at least one pawn for additional compensation and sometimes two pawns (which is no sac at all). And the second link shows only pawn sacs, not exchange sacs. So these links are making my case for me .... programs don't seem to sac a full exchange for purely positional compensation.

I have seen some versions of Rybka make the right move here:
[d]r1bqk1nr/pppp1ppp/2n5/b7/2BpP3/2P2N2/P4PPP/RNBQ1RK1 b kq - bm Nge7;

Though most engines will toil for hours, scheming about capturing that lovely pawn.

[Mike S.]

I am sure if you do a database search over CCRL or CEGT games, you will find MANY successfull sacrifices of a FULL exchange. Of course, you would need to review it from the human perspective, if they are to be considered tactically or positionally.

I would start with Quad-Rybka games and/or with the 40/120 downloads from CEGT, for this search.

Another engine which is capable of BIG longe-range sacrifices, is Junior (maybe older versions even more than the latest).

[Graham Banks]

I am sure if you do a database search over CCRL or CEGT games, you will find MANY successfull sacrifices of a FULL exchange. Of course, you would need to review it from the human perspective, if they are to be considered tactically or positionally.

I would start with Quad-Rybka games and/or with the 40/120 downloads from CEGT, for this search.

Another engine which is capable of BIG longe-range sacrifices, is Junior (maybe older versions even more than the latest).

Yes, Robin could use the following tool to search databases specifically for full exchange sacs:
http://www.rbnn.com/cql/

Regards, Graham.

[smirobth]

I looked for examples four or so years ago and couldn't find any.

I asked for some help on the Rybka forum and Vas replied:

Graham,

I definitely agree with your comment. For some ancient examples, take a look here:

http://www.rybkachess.com/index.php?aus ... hange+sacs
http://www.rybkachess.com/index.php?aus ... sacrifices

Newer Rybka versions are even much better at this.

Vas

Thanks Graham. However in the first link you provided every single exchange sac involved not only positional compensation, but also at least one pawn for additional compensation and sometimes two pawns (which is no sac at all). And the second link shows only pawn sacs, not exchange sacs. So these links are making my case for me .... programs don't seem to sac a full exchange for purely positional compensation.

I have seen some versions of Rybka make the right move here:
[d]r1bqk1nr/pppp1ppp/2n5/b7/2BpP3/2P2N2/P4PPP/RNBQ1RK1 b kq - bm Nge7;

Though most engines will toil for hours, scheming about capturing that lovely pawn.

This Evan's gambit position is an example of avoiding a pawn sac, not offering an exchange sac. Also in this position d6 is just as good as Nge7, so perhaps this would be better as an avoid move position. It is an nice position to test comps with though. Taking the pawn is very bad but not obvious.

[smirobth]

I am sure if you do a database search over CCRL or CEGT games, you will find MANY successfull sacrifices of a FULL exchange. Of course, you would need to review it from the human perspective, if they are to be considered tactically or positionally.

I would start with Quad-Rybka games and/or with the 40/120 downloads from CEGT, for this search.

Another engine which is capable of BIG longe-range sacrifices, is Junior (maybe older versions even more than the latest).

Yes, Robin could use the following tool to search databases specifically for full exchange sacs:
http://www.rbnn.com/cql/

Regards, Graham.

Thanks Graham. I haven't used this program before. I have chessbase, but it is not a simple task to find exchange sacs with chessbase. Can you give me an example of how to define a CQL query for an exchange sac? Their sac example shows only a queen sac, but an exchange sac is a lot harder to define since it involves a rook on one side and either a bishop or knight on the other (not just one piece).