Showing posts with label Rybka. Show all posts
Showing posts with label Rybka. Show all posts

Tuesday, September 18, 2018

Jerome Gambit: Centaurs

Image result for free clip art centaur



Recently Bill Wall sent me 16 of his Jerome Gambit games that were Human + Computer vs Computer encounters. Such teamwork is sometimes referred to as advanced chess, or cyborg chess, or centaur chess.

Over the years, I have posted games from Human vs Computer matches (including the legendary 1993 Fisher-Kirshner - Knight Stalker battles, and the rolling 2006 RevvedUp - Fritz 8 - Crafty 19.19 - Hiarcs 8 - Shredder 8 - Yace Paderborn mayhem) as well as many Computer vs Computer games, but I think this is the first centaur chess I have presented.

The results are interesting - even if it is difficult to assign the relative impact that the human had on the play. Also, the time controls, which affect the strength of computer programs, are not known.

Over all, White scored 4 - 9 - 3 (34%), which would be unimpressive for a normal opening under normal circumstances, but which seems - as with all Jerome Gambit matches - a bit "high" for a many-times-refuted opening.

A little more insight is available by breaking the games down into 4-game matches.

Crafty vs Stockfish + Wall, for example, yielded 2 wins for Black when played by the team; and, likewise, 2 wins for White when played by the team. With all due respect to Dr. Robert Hyatt's computer engine, it appears it could have been simply outplayed by its stronger computer opponent. Who played what color did not seem to matter.

On the other hand, the Komodo 5 vs Rybka + Wall match, which ended with a score of 2 - 2 - 0, was composed of 4 wins by Black. Neither engine, it appears, was able to ovecome the "handicap" of playing the Jerome Gambit.

The Hiarcs 9 vs Critter + Wall match seemed a reflection of the comparative strengths of the computer programs, as Hiarcs 9 lost 2 games as White, and could only manage a draw as Black.  

Interesting, also, was the Fritz 12 vs Houdini + Wall match. The team was 1 - 0 - 1 as White, and 1 - 0 - 1 as Black, suggesting that Houdini was the brighter computer program.

Looking at a couple of lines of play, 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Kxf7 5.Nxe5+ Nxe5 6.d4 scored 2 - 5 - 1, while 6.Qh5+ scored 2 - 4 - 2, not much of a difference.

I will be sharing some of the games, taking a look at what "theoretical" enlightenment they bring. 
  

Thursday, July 13, 2017

Jerome Gambit: First There Is The Confusion Factor

I am reading IM Sam Collins' Gambit Busters* (Everyman Chess, 2010) with a know-your-enemy focus, and enjoyed the following, from the chapter "Escaping the Defensive Mindset"
It is well known that club players, typically, go to pieces when confronted by a gambit. Of course, for every player there are some gambit lines which they know, and perhaps their theoretical knowledge will suffice to get them to a safe position. But this won't be the case when they are confronted by an established gambit they don't know, an unusual or forgotten gambit, or where their opponent deviates from theory. 
To my mind, gambits are the situations where there is the single biggest gap between passively looking at a position at home, and facing something over the board. Skimming over an opening variation with a cup of tea, maybe Rybka muttering in the background, it all looks so straightforward - an "=" symbol (or something even more favourable), a bunch of crisp responses demonstrating the intellectual failure of our opponent's adventure. 
But at the board, things are rather different. First, there is the confusion factor...

Yes, indeed. At the level of play that the Jerome Gambit is exhibited, it is often "unusual" or "forgotten" enough to lead to success. Certainly it can lead to "confusion".

"Knowing" that the opening is refuted, looked askance at by "the book" and hooted at by computers, it must be infuriating (or embarassing) for the defender to be struggling against such a monstrosity.

I am remined of the story about chess great Aaron Nimzovich climbing on a table and bemoaning "Why must I lose to this idiot?" More recently, Bill Wall shared the scolding he received from his opponent after having the audacity to play - and win with - the Jerome Gambit. The opening is garbage, it would never work against a grandmaster, the world champion would never play such a thing...

Ah, yes. In my pre-Jerome Gambit days I would repeatedly defeat a friend who always protested "But I was winning!" I would reassure him that, yes, he was winning, right up to the point where I checkmated him.


(*I am enjoying Collins' work, and I appreciate the classic games that he chooses to illustrate his points. I was surprised, however, in the mentioned chapter, that after all that he wrote of the tribulations of "club players" he chose a game between super-Grandmasters Anand and Shirov to drive the point home.)

Saturday, October 29, 2016

Jerome Gambit: Little Surprises

!?!?


While the Jerome Gambit might, on the surface, appear to be a "simple" chess opening - so brutal as to be completely transparent - it can have its little surprises, which is part of what makes it attractive. Take the following game...

procyk - deriver69
Jerome Gambit Tournament, RedHotPawn.com, 2016

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+



4...Kxf7 5.c3 Nf6 6.O-O d6 7.d4 exd4 8.cxd4 Bb6 9.Qb3+ Ke7 



It is interesting that Stockfish 7 prefers 9...d5 here, while a couple of other computers in game situations preferred 9...Kf8, e.g. 10.Qd3 (10.d5 Ne5 11.Nxe5 dxe5 12.Nc3 Ng4 13.h3 Bxf2+ 14.Rxf2+ Nxf2 15.Kxf2 Qh4+ 16.Kg1 Qg3 17.Nb5 Qxb3 18.axb3 c6 19.Nc7 Rb8 20.Be3 Bd7 21.Bxa7 Rd8 22.Rf1+ Kg8 23.Bc5 cxd5 24.exd5 h6 25.Re1 Rc8 26.d6 Rh7 27.b4 g6 28.Nd5 Rf8 29.Rxe5 Rhf7 30.Re1 Re8 31.Ne7+ Kh7 32.Ra1 Ref8 33.b3 Rf4 34.Ra7 Rb8 35.Bb6 Rf7 36.Bc7 Rbf8 37.Rxb7 Bxh3 38.Bb6 Bc8 39.Ra7 Be6 40.d7 Rf1+ 41.Kh2 Rd1 42.d8=Q Rdxd8 43.Bxd8 Rxd8 44.b5 Rd3 45.Nc6+ Kg8 46.b6 Rxb3 47.b7 Bc4 48.b8=Q+ Rxb8 49.Nxb8 Be6 50.Nc6 h5 51.Kg3 Kf8 52.Kf4 Bd5 53.Ne5 Bxg2 54.Nxg6+ Ke8 55.Kg5 Bf3 56.Nf4 Kd8 57.Nxh5 Kc8 58.Rg7 Be4 59.Kf4 Bc6 60.Ke5 Bf3 61.Nf4 Bc6 62.Ne6 Kb8 63.Kd6 Be4 64.Nd4 Kc8 65.Rc7+ Kb8 Black resigned, Rybka 2.3.2a - DrunkenMaster 1.2, 2009) 10...Qe7 11.Nc3 Bg4 12.Be3 Nb4 13.Qd2 Bxf3 14.gxf3 Kg8 15.Na4 Nc6 16.Rac1 Qf7 17.b4 Qg6+ 18.Kh1 Qh5 19.Qd1 Rc8 20.Nxb6 axb6 21.Rg1 Nxb4 22.Qb3+ Kf8 23.Qxb4 Qxf3+ 24.Rg2 Qxe4 25.Bg5 Qd5 26.Bxf6 gxf6 27.Qd2 h5 28.Qf4 f5 29.f3 Rh7 30.Rg6 Ra8 31.Rf6+ Ke8 32.Rxf5 Qg8 33.Qe4+ Kd8 34.Qxb7 Rc8 35.Rf6 Ke7 36.Rf4 Kd8 37.Re4 Qf7 38.f4 Rg7 39.Rce1 Rg8 40.Qc6 Qd7 41.Qd5 Qg4 42.Re7 Qg6 43.Qc6 Qg1+ 44.Rxg1 Rxg1+ 45.Kxg1 Kxe7 46.f5 Kf6 47.Qg2 Re8 48.Qg6+ Ke7 49.Qg7+ Kd8 50.f6 Kc8 51.f7 Black resigned, SOS 5.1 - DrunkenMaster, 2009.

In any event, Black appears to be doing well, having an extra piece for the cost of a pawn. True, his King has not found safety, but isn't that a trivial thing?

7.Bg5

White pins the Knight, setting up a hit on it with the e-pawn. It turns out that he can make the advance right away: 7.e5 dxe5 8.dxe5 Ne4 9.Ng5!? Here's a shocker; White recovers his piece. Stockfish 7 recommends 9...Qg8 10.Qxg8 Rxg8 11.Nxe4 h6 and White has a small edge.

7...Bg4 8.e5 dxe5 

9.Nxe5 

Deviating from the foretold 9.dxe5. Maybe he can still get a pawn to e5?

9...Nxe5 

Black believes he has an antidote to all the mischief regarding the e5 pawn's attack on the pinned Knight at f6, but he should have played it - 9...Be6 - right away, as after 10.Nxc6+ bxc6 11.Re1 Qd6 he would be doing fine.

10.dxe5 Be6 11.exf6+ gxf6 12.Qa3+ Kf7 



White has recovered his piece, and Black's King remains slightly exposed. If the first player can safeguard his Bishop, he should be able to keep the game level.

13.Bh4 

This looks fine, but Stockfish 7 recommends the pin, 13.Qf3, instead, i.e. 13...Qd4 14.Nd2 Bg4 15.Qb3+ Be6 16.Qf3 and an invitation to draw by repetition. Existential anxiety?

13...Rg8

This proves to be the winning idea, but the computer prefers 13...Qd4 14.Bg3 h5 15.Qc3 h4 16.Qxd4 Bxd4 17.Bxc7 Bxb2 18.Nd2 Bxa1 19.Rxa1 Bd5 when Black is clearly better.

14.Nc3 Bd4 15.Ne2 Qd5 16.Rad1 



Suddenly realizing that he had overlooked something, here White resigned

Friday, June 17, 2016

Different Analysts, Same Outcome



Torneo tematico GaJero00-A  2009

                      1 2 3 4 5 6 7 8

1 Rybka 2.3.2a (2 CPU) ** 11 01 01 11 11 11 11.5/14
2 WB Nimzo 2000b       00 ** 01 11 11 ½1 11 10.0/14
3 SOS 5.1              10 10 ** 00 11 11 11 ½1 9.5/14
4 Comet B48            10 00 11 ** 10 01 11 11 9.0/14
5 Zarkov 4.70          0½ 00 01 ** 01 11 6.5/14
6 DrunkenMaster 1.2 00 00 00 10 ** 10 11 4.5/14
7 La Dame Blanche 2.0c 00 ½0 00 00 10 01 ** 01 3.5/14
8 Demon 1.0            00 00 ½0 00 00 00 10 ** 1.5/14


The following game from the Jerome Gambit thematic chess tournament presented at the Scacchi64.com website provides a framework for how a number of computer chess programs address a particular opening line. (I have been guided in my own assessments by Stockfish 7.)

La Dame Blanche 2.0c - Comet B48
Torneo tematico GaJero00-A, 2009

 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 



4...Kxf7 5.O-O Nf6 6.Nxe5+ Nxe5 7.d4 Qe7



A bit better is 7... Bxd4 8. Qxd4 d6 (8...Nc6 9. Qc4+ [9. Qa4 Qe7 10.Nc3 Qb4 11.Qxb4 Nxb4 12.e5 Nxc2 13.Rb1 Ne8 14.Bf4 c5 15.h3 b6 16.Rbc1 Nd4 17.Rcd1 Ba6 18.Rfe1 Kg6 19.Rd2 Nc7 20.Be3 Nce6 21.a3 Rhf8 22.b4 Rf5 23.bxc5 bxc5 24.f4 Nxf4 25.Bxf4 Rxf4 26.Nd5 Rff8 27.Nc7 Bb5 28.Rxd4 cxd4 29.Nxb5 Rf4 30.e6 d3 31.Rd1 dxe6 32.Rxd3 Kf6 33.Kh2 a5 34.Kg3 g5 35.Rd7 Rb8 36.Nd6 Rb3+ 37.Kh2 Kg6 38.Rc7 Rxa3 39.Nc4 Ra2 40.Ne5+ Kf5 41.Nd3 Rd4 42.Rf7+ Ke4 43.Nf2+ Kd5 44.Rd7+ Kc4 45.Rc7+ Kb5 46.Rf7 Rdd2 47.Kg1 Rxf2 48.Rxf2 Rxf2 49.Kxf2 Kc4 50.Ke1 Kc3 51.Kd1 Kb2 52.Ke2 Kc2 53.Kf3 White resigned, Demon 1.0 - Rybka 2.3.2a, Torneo tematico GaJero00-A, 2009] 9...d5 10.exd5 Qxd5 11.Qxd5+ Nxd5 12.c4 Ndb4 13.Nc3 Bf5 14.Bf4 Nd3 15.Nd5 Nxb2 16.Nxc7 Rac8 17.Nb5 Nxc4 18.Rac1 a6 19.Nc7 N6e5 20.h3 Rxc7 21.Bxe5 Rc6 22.Bf4 Re8 23.Rc3 Re4 24.Rf3 Re2 25.a3 Be4 26.Rc3 Nb2 27.Rg3 Rcc2 28.Be3 Nc4 29.Bd4 g6 30.Kh1 Rcd2 31.Ba7 b6 32.Kg1 Ra2 33.Rc1 Bd5 34.Rd1 Ke6 35.Kh1 Rxf2 36.Re1+ Kd7 37.Rg1 Kc6 38.Rg5 Ne3 39.Rc1+ Kb7 40.Bxb6 Kxb6 41.Rb1+ Kc5 White resigned, La Dame Blanche 2.0c - Rybka 2.3.2a, Torneo tematico GaJero00-A, 2009) 9.f4 Nc6 10.Qd3 Re8 11.Qc4+ (11.Nc3 Kg8 12.f5 Ne5 13.Qg3 Nf7 14.Re1 b6 15.Bd2 Bb7 16.Qf4 Re5 17.Qf3 Qe8 18.Bf4 Bxe4 19.Nxe4 Rxe4 20.Rxe4 Qxe4 21.Qxe4 Nxe4 22.Re1 Re8 23.h4 Nf6 24.Rxe8+ Nxe8 25.Kf2 Ne5 26.Bc1 Nf6 27.Ke2 Kf7 28.Bg5 Nd5 29.h5 h6 30.Bd8 c5 31.b3 Nc6 32.c4 Nxd8 33.cxd5 Kf6 34.Kd3 Kxf5 35.Kc4 Ke4 36.Kb5 Kxd5 37.g3 a6+ 38.Kxb6 c4 39.bxc4+ Kxc4 40.Kc7 d5 41.Kxd8 Kd3 42.g4 Ke3 43.a4  White resigned, La Dame Blanche 2.0c - WB Nimzo 2000b,Torneo tematico GaJero00-A, 2009) 11...Be6 12.Qa4 Kg8 13.Nc3 a6 14.f5 Bf7 15.Qa3 Nd4 16.Rb1 Qd7 17.Rf2 Nxe4 18.Nxe4 Rxe4 19.Be3 Nxf5 20.Bg5 h6 21.Bd2 Nd4 22.Qd3 Rae8 23.Rbf1 Ne2+ 24.Kh1 Rd4 25.Qf3 Bd5 26.Qe3 Rxe3 27.Bxe3 Re4 28.Rxe2 Bc4 29.Ra1 Bxe2 30.Bd2 Qf5 31.Re1 White resigned, La Dame Blanche 2.0c - Zarkov 4.70,Torneo tematico GaJero00-A, 2009.

Also a bit better than the text is 7...d5 8.dxe5 Nxe4 9.Be3 Rf8 (9...Bxe3 10.fxe3+ Kg8 11.Nc3 Nxc3 12.bxc3 Be6 13.Qd4 Rc8 14.Qxa7 Qg5 15.Qd4 c6 16.Rf3 h5 17.Rb1 b5 18.h4 Qg6 19.Rb2 Re8 20.Rf2 Ra8 21.Qb4 Rh6 22.Qf4 Qe8 23.Rd2 Rg6 24.Rd4 Qe7 25.Rd1 Rf8 26.Qb4 c5 27.Qxb5 Rxg2+ 28.Kxg2 Qxh4 29.Qe2 Bg4 30.Rh1 Qg5 31.Qf1 Be2+ 32.Kh2 White resigned, Demon 1.0 - WB Nimzo 2000b, Torneo tematico GaJero00-A, 2009) 10.Bxc5 Nxc5 11.b4 Ne6 12.Nc3 c6 13.Qc1 Kg8 14.Ne2 Qb6 15.a3 Rf5 16.Qb2 Qc7 17.f4 g5 18.g4 Rxf4 19.Nxf4 Nxf4 20.Rae1 Bxg4 21.Kh1 Re8 22.Rxf4 gxf4 23.Rg1 h5 24.h3 Qh7 25.c4 Kf7 26.hxg4 hxg4+ 27.Qh2 Qe4+ 28.Rg2 Kg7 29.c5 g3 30.b5 Rh8 31.Qxh8+ Kxh8 32.bxc6 White resigned, Demon 1.0 - Zarkov 4.70, Torneo tematico GaJero00-A, 2009 

8.dxc5 Qxc5 9.Nc3

Or, 9.Be3 Qb4 10.Bd4 Nc6 11.Bxf6 gxf6 12.Qd5+ Kg7 13.Nc3 Qxb2 14.Qd3 Ne5 15.Qd2 Qb4 16.Rab1 Qc5 17.Rb5 Qc6 18.Qe3 d6 19.f4 Ng6 20.f5 Ne5 21.Rf4 b6 22.Qg3+ Kf7 23.Rd5 Bb7 24.Qe3 Rag8 25.h3 Rg7 26.Rd4 Rhg8 27.g4 h5 28.Kf1 Ba6+ 29.Kf2 hxg4 30.h4 Rh8 31.Ra4 Rxh4 32.Rxa6 g3+ 33.Kg1 Rxf4 34.Qxf4 Qc5+ 35.Kg2 Qxc3 36.Ra3 White resigned, Demon 1.0 - Comet B48,Torneo tematico GaJero00-A, 2009 

9...d6

White has only a pawn for its sacrificed piece, but has some play against Black's uncastled King.

10.Bg5 Be6 11.Bxf6 gxf6 12.Qh5+ Ke7 13.Rab1 



This is a mysterious Rook move, indeed. Perhaps better was 13.Kh1, preparing 14.f4.

13...Rag8 14.Rfe1 Rg4 15.Qh3 Rhg8 16.Kh1 Rxg2



Removing White's King's protection.

17.Qxg2 Rxg2 18.Kxg2 Ng4 19.Re2 Qe5 20.f4 Qxf4 21.Kg1 Kd7 22.Rd1 Bc4 23.Red2 Qg5 24.Kh1 Qc5



White has no counterplay and soon will be vanquished.

25.Na4 Qe3 26.Nc3 Bf1 27.Nd5 Qf3+ 28.Kg1 Be2 29.Nxf6+ Nxf6 30.Rd3 Bxd3 31.Rxd3 White resigned



Wednesday, June 15, 2016

What Can We Learn From the Robots?



Torneo tematico GaJero00-A  2009

                      1 2 3 4 5 6 7 8

1 Rybka 2.3.2a (2 CPU) ** 11 01 01 11 11 11 11.5/14
2 WB Nimzo 2000b       00 ** 01 11 11 ½1 11 10.0/14
3 SOS 5.1              10 10 ** 00 11 11 11 ½1 9.5/14
4 Comet B48            10 00 11 ** 10 01 11 11 9.0/14
5 Zarkov 4.70          0½ 00 01 ** 01 11 6.5/14
6 DrunkenMaster 1.2 00 00 00 10 ** 10 11 4.5/14
7 La Dame Blanche 2.0c 00 ½0 00 00 10 01 ** 01 3.5/14
8 Demon 1.0            00 00 ½0 00 00 00 10 ** 1.5/14


The crosstable above is for the Jerome Gambit thematic chess tournament presented at the Scacchi64.com website, referred to in a couple of earlier posts (see "The Macbeth Attack" and "From the Scacchi64.com Jerome Gambit Thematic").

It is not surprising that the tournament leader, Rybka, had the best score with the Jerome Gambit, with 4 wins and a draw. (It climbed to the top by beating the Jerome 7-0. I know how that goes: see "Overrated!")

The next finishers - WB Nimzo, SOS and Comet - all had 3 wins. They were followed in the standings by Zarkov and DrunkenMaster, each with 1 Jerome Gambit win.

Of note, half of the games featured the "classical" 5.Nxe5+, with White scoring 34% (versus 54% in The Database) while half had the "modern" 5.0-0, with White scoring 29% (versus 38% in The Database). 

Interestingly, Rybka played 5.0-0 in all 7 of its games with White and scored 64%, WBNimzo and Comet, the #2 and #4 finishers, all played 5.Nxe5, while 3rd place finisher SOS stuck with 5.0-0.

Perhaps the most "psychological" opening move played in a winning effort - and here I mean the kind of move that would emotionally effect an opponent, if the opponent, indeed, were succeptible to feeling emotions - came in the following game.

DrunkenMaster 1.2 - La Dame Blanche 2.0c
Torneo tematico GaJero00-A, 2009

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 



4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 7.f4 d6



The "Silicon Defense", very popular with computers.

8.fxe5 dxe5 9.Qh3+ Ke7 10.Qg3 Qd4



Not the best move, but good and scary - if your opponent can be scared. I doubt that La Dame Blanche shook to its bits, but it might be a good move to try against a human!

11.Qxg7+

White blunders immediately, but surely this must be a coincidence?

Two other choices: 11.Nc3 Kf7 12.d3 Nf6 13.Rf1 Be6 14.Bd2 Rhf8 15.O-O-O Kg8 16.Nb5 Bb6?? 17.Nxd4 Bxd4 18.c3, Black resigned, MrJoker - rgiblon, Internet Chess Club, 2013; and

11.d3 (best) Kf7 12.c3 Qd8 13.d4 exd4 14.b4 Be7 15.O-O+ Ke8 16.Qxg7 Bf6 17.Qg3 Qe7 18.Bf4 a5 19.e5 Bh4 20.Qf3 axb4 21.cxd4 Qf7 22.g3 Be7 23.Rf2 h5 24.Qe4 h4 25.Nd2 Qf5 26.Qf3 Nh6 27.Nf1 Ng4 28.Ne3 Nxe3 29.Qxe3 Be6 30.Qf3 hxg3 31.hxg3 c6 32.g4 Qg6 33.Bh2 Rh4 34.Rg2 Bd5 35.Qf5 Qxf5 36.gxf5 Bxg2 37.Kxg2 Rxd4 38.Bg1 Rd2+ 39.Kf1 b3 40.f6 b2 41.Rb1 Rad8 42.Be3 Rd1+ 43.Kf2 Rxb1 44.fxe7 Rd5 White resigned, Junior 7 -Fritz 8, The Jeroen Experience, 2003.

11...Kd6

Somewhat better was 11...Ke8, 12. Nc3 Qf2+ 13. Kd1 Nf6 14. Re1 Rg8 15. Qxg8+ Nxg8 16. Ne2 Qxg2 17. d4 Bxd4 White resigned, Fritz 5.32 - Fritz 8, The Jeroen Experience 2003

12.Kd1

The text is better than White's other choice in the tournament: 12.d3 Qf2+ 13.Kd1 Nf6 14.Bg5 Bg4+ 15.Kc1 Be3+ 16.Bxe3 Qxe3+ 17.Nd2 Raf8 18.d4 Rhg8 19.dxe5+ Kc6 20.Qe7 Nxe4 21.Qb4 Nxd2 22.Qxd2 Qxd2+ 23.Kxd2 Be6 24.g3 Rf2+ 25.Ke3 Rf5 26.Rhe1 Rxe5+ 27.Kf2 Rf5+ 28.Kg1 Bd5 29.c4 Bf3 30.Re6+ Kd7 31.Rae1 h5 32.Re7+ Kc8 33.R1e5 Rff8 34.Rc5 c6 35.Ra5 Kb8 36.Ra3 Rg5 37.Rae3 Bg4 38.b4 Bc8 39.c5 Rd5 40.R7e5 Bh3 41.Re8+ Rxe8 42.Rxe8+ Kc7 43.Kf2 Rd2+ 44.Re2 Rxe2+ 45.Kxe2 Bg4+ 46.Ke3 b6 47.Kd4 a5 48.a3 a4 49.Kc3 b5 50.Kd3 Kd7 51.Ke3 Ke7 52.Kd3 Kf6 53.Ke4 Bf5+ 54.Kf4 Bh3 55.Ke4 Ke6 56.Kd4 Bf5 57.h3 Bxh3 58.Ke4 White resigned, Zarkov 4.70 - La Dame Blanche 2.0c, Torneo tematico GaJero00-A, 2009

12...Qxe4 13.h3 Qg6



14.Qxh8

This leads to checkmate in 11 moves. (These are computer chess players we are talking about.) 

14...Qh5+ 15.Ke1 Qh4+ 16.Ke2 Bxh3 17.Rxh3 Qf2+ 18.Kd3 Qf1+ 19.Ke4 Qxg2+ 20.Rf3 White resigned



There follows 20...Qg4+ 21.Rf4 Qxf4+ 22.Kd3 Qf3+ 23.Kc4 Qe4+ 24.Kc3 Qd4+ 25.Kb3 Kb4 checkmate


Monday, June 13, 2016

From the Scacchi64.com Jerome Gambit Thematic



Torneo tematico GaJero00-A  2009

                      1 2 3 4 5 6 7 8

1 Rybka 2.3.2a (2 CPU) ** 11 01 01 11 11 11 11.5/14
2 WB Nimzo 2000b       00 ** 01 11 11 ½1 11 10.0/14
3 SOS 5.1              10 10 ** 00 11 11 11 ½1 9.5/14
4 Comet B48            10 00 11 ** 10 01 11 11 9.0/14
5 Zarkov 4.70          0½ 00 01 ** 01 11 6.5/14
6 DrunkenMaster 1.2 00 00 00 10 ** 10 11 4.5/14
7 La Dame Blanche 2.0c 00 ½0 00 00 10 01 ** 01 3.5/14
8 Demon 1.0            00 00 ½0 00 00 00 10 ** 1.5/14



The crosstable above is for the Jerome Gambit thematic chess tournament presented at the Scacchi64.com website, referred to in an earlier post (see "The Macbeth Attack").

As can be seen, 56 games games were played (with an average of 51 moves) with White scoring 31%.

This compares to the 12,478 games in The Database with the 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ move order,  with White scoring 45%, in games averaging 31 moves.

The difference in performance for White between the tournament and the larger collection can be in part attributed to sampling bias (players tend to more often publish their wins with their favorite openings, rather than their losses, and these could be over-represented in The Database) but the fact that about 80% of the relevant Jerome Gambit games in The Database are drawn from 17 years of games from the Free Internet Chess Server (FICS) - regardless of outcome - mitigates against that. It is likely that computers defend better than average club players when it comes to facing "refuted" opening play.

The difference in average game length between the two collections can be attributed to computer engines tendency to play to mate. It is interesting to point out several long games from the thematic tournament


WB Nimzo 2000b - La Dame Blanche 2.0c

drawn after 109 moves, via the 50-move rule; little progress can be expected in this Bishops-of-opposite-colors endgame anyhow




Zarkov 4.70 - DrunkenMaster 1.2

drawn after 93 moves, again via the 50 move rule


Some of the endgames were quite hard-fought, however. Consider the following position, from Rybka 2.3.2a - Zarkov 4.70, after 62.Kg7




There is a lot going on, even for a computer chess engine to grasp. Black wins by giving up his Knight and bringing his Rook back to exchange itself for White's advanced passed pawn (!) with 62...Rd2! 63.Kxf7 Rd7+ 64.Kg6 Rxh7 65.Kxh7 b4 and Black's passers will produce a winning Queen.

Instead, the game continued

62...Rh2!? 

A very direct move and sacrifice that, unfortunately, serves only to draw.

63.Rxh2 a1=Q 64.Kxf7 Qa7+ 

Black must check the enemy King and hold the enemy pawns back, hoping for repetition.

65.Kg6 Qb6+ 66.Kh5 Qd4 67.Rh3+ 


White, too, must worry about the enemy passed pawn - as well as the fact that Black has Q vs R.

67...Kc2 68.g5 b4 69.Rh2+ Kc3 70.Rh3+ Kb2 71.Rd3 


Nice. If Black now takes the Rook, White Queens his h-pawn. Either way, however, the game remains drawn.

71...Qh8 72.g6 Qf6 73.Rg3 Qg7 74.Re3 Qf8 75.Re7 


The same idea as above: taking the Rook leads to pawn promotion (and a draw).

75...Qf5+ 76.Kh6 Qf8+ 77.Kh5 Qh8 78.Kh6 Qd8 79.g7 


It looks like Rybka will finally break through, but Zarkov has the half-point in hand.

79...Qd6+ 80.Kh5 Qh2+ 81.Kg6 Qc2+ 82.Kh6 Qh2+ 83.Kg6 Qc2+ 84.Kh6 Qh2+ 85.Kg6 drawn




Thursday, December 10, 2015

Correspondence Play (Part 1)


Alonzo Wheeler Jerome developed and defended his gambit in both across-the-board and correspondence games in the late 1800s and early 1900s. He even arranged to play the Jerome Gambit against readers of the Literary Digest.

In modern times, however, the Jerome is most likely to show up in internet games, often blitz; although the occasional face-to-face contest still can be found.

Recently, I received an email from Vlastimil Fejfar, of the Czech Republic, who shared three of his Jerome Gambit correspondence games - a pleasant return to the days of AWJ.

Fejfar,V - Pressl
corr Czech Republic, 2015

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+


4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 7.f4 d6



White faces what I have called "the annoying defense", where Black calmly gives back a piece and avoids any risky misadventures, remaining up a piece for a pawn.

The idea is at least as old as D'Aumiller, A.D. - A.P., Livorno, 1878 (1-0, 19). It is the choice of many computer programs in games in The Database, including Fritz, Hiarcs, Junior, Rybka, Shredder and Spike; so I have also referred to it as "the silicon defense".

Also, 7...d6 is the move recommended by many authorities, including IM Gary Lane in his The Greatest Ever Chess Tricks and Traps.

Vlasta proceeds calmly against it.

8.fxe5 dxe5 9.Qh3+ Kd6 10.Qd3+ Ke7 11.Qg3 Ke6 12.Qb3+ Ke7 13.Qg3 Ke6 14.Qb3+ Ke7 15.Qg3 



Drawn

It is not clear who came out "ahead" in this encounter, Black, who was able to split the point, or White, who was able to play a "refuted" opening and not lose.

I am sympathetic. The second round of the Chess.com Italian Game Tournament has concluded for me, again (like in the first round) without being able to contest a single Jerome Gambit, which my opponents dodged. With White I scored two wins (one on time), four draws and no losses. Did more than half of my opponents "succeed" in "winning half a point" against me, or did they miss out on strolling to victory?



[This is blog post number 2,150, for those who might wonder. - Rick]