Showing posts with label SOS. Show all posts
Showing posts with label SOS. Show all posts

Monday, May 22, 2017

Lewis Gambit

I have been enjoying watching the series of "Dirty Chess Tricks" videos on YouTube, by Gunjan Jani, especially "Dirty Chess Tricks 13" on the Lewis Gambit, 1.e4 e5 2.Bc4 Bc5 3.d4.

This is an opening line that I have touched upon in this blog, starting with "SOS", writing about Secrets of Opening Surprises, Volume 10, which contained an article by Jeroen Bosch on the Lewis Gambit.  

The earliest examples I have of the gambit are from an 1841 Staunton - Cochrane match, which makes it a possible inspration for Alonzo Wheeler Jerome in creating his Jerome Gambit, after the Lewis line 3...exd4 4.Bxf7+. The similarity to the Abrahams Jerome Gambit - 1.e4 e5 2.Bc4 Bc5 3.Bxf7+ - is apparent. See "Proto-Jerome Gambits? (Part 4)".

There is also a similarity to a line in the Von der Lasa Gambit, 1.e4 e5 2.d4 exd4 3.Bc4 Bc5 4.Bxf7+, as seen in J.H. Blackburne - E.J. Evelyn, blindfold, London, 1862 (1-0, 32). And let's not overlook the "Macbeth Attack".

Jani rightly points out the possibilities of the Lewis Gambit transposing to the Max Lange Gambit, the Max Lange Attack, and the Italian Gambit.

(GM Boris Alterman has a video on the Lewis Gambit as well. Dangerous Weapons: 1.e4 e5 by GM John Emms, GM Glenn Flear, and IM Andrew Greet has good coverage of where the Lewis Gambit can go if Black does not allow a Bxf7+.)


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

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




Monday, November 5, 2012

Proto-Jerome Gambits? (Part 4)


Of course, as Alonzo Wheeler Jerome was putting together his ideas on the Jerome Gambit, he might well have been influenced by the games of Joseph Henry Blackburne, whose aggression often showed up in sharp attacks like the one after 1.e4 e5 2.d4 exd4 3.Bc4 Bc5 4.Bxf7+ as we have seen before; or, a move later, here.

(A correspondence game played after Jerome passed on is still worth passing along again.)

Coming out of the move order that we have been looking at, 1.e4 e5 2.Bc4 Bc5 3.d4 exd4 the Lewis Gambit, reaches the same position after 4.Bxf7+, and, as the earliest example was Staunton - Cochrane, match, 1841, the line was likely available to Jerome as well. 

It is also available to Readers who would like to check out Secrets of Opening Surprises, Volume 10, edited by Jeroen Bosch, where the Lewis Gambit is examined. 

Sunday, June 12, 2011

Sunday Book Review: S.O.S. # 13

In my writing at Chessville (alas, the site is still without new content) I have reviewed a number of books in the Secrets of Opening Surprises series (#4, #6, #7, #8, #9, #10, #11, #12), edited by Jeroen Bosch. They are surprisingly addictive, sometimes startling, and always creative. As the series describes itself,

No time to study main lines? Shock your opponent with an SOS!... Secrets of Opening Surprises brings you a wide variety of unusual opening ideas. They may seem outrageous at first sight, but have proven to be perfectly playable.

After the introductory "S.O.S. Files", chronicling how earlier suggestions have worked out in over-the-board combat, Volume #13 contains:

- Sicilian Najdorf: the Czebe Attack (1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Qe2!?) GM Arthur Kogan

- The North Sea Defence (1.e4 g6 2.d4 Nf6) IM Jeroen Bosch

- The Williams Anti-Grünfeld Variation (1.d4 Nf6 2.c4 g6 3.h4) GM Simon Williams

- The Scotch Game: Carlsen Leads the Way (1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Nb3 Bb6 6.Nc3 Nf6 7.Qe2) GM Konstantin Landa

- The Budapest Gambit Delayed (1.d4 Nf6 2.c4 e6 3.g3 e5) IM Jeroen Bosch

- French Defence: Obtaining Two Bishops (1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Nge2 dxe4 5.a3 Bxc3+ 6.Nxc3) GM Alexander Finkel

- Grabbing a Pawn in the Réti/Catalan (1.Nf3 d5 2.g3 c5 3.Bg2 Nc6 4.d4 e6 5.0-0 Bd7 6.c4) GM Glenn Flear

- Sicilian: Karma Chameleon (1.e4 c5 2.Ne2 d6 3.c3) GM Dimitri Reinderman

- The Centre Game in Viking Spirit (1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qa4) IM Jeroen Bosch

- Slav: The Easy Way (1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nbd2) GM Efstratios Grivas

- Spanish: Kortchnoi's Idea in the Central Attack (1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d4 Nxd4) GM Adrian Mikhalchishin

- Panic in the London (1.d4 Nf6 2.Nf3 d6 3.Bf4 Nh5) GM Dimitri Reinderman

- Pirc Defence - Taking off the Gloves (1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 0-0 6.e5 Nfd7 7.h4) GM Alexander Finkel

- New Recipe in Old Indian (1.d4 Nf6 2.c4 d6 3.Nc3 e5 4.Nf3 Nbd7 5.e4 Be7 6.Be2 0-0 7.g4) IM Jeroen Bosch

- Sicilian Mission: To Boldly Go... (1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 a6 6.Bf4 d6 7.Bg3) GM John van der Wiel

- Surprising Sacrifice in the Giuoco Piano (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Bd2 Bxd2+ 8.Qxd2!) GM Ian Rogers

Another fine collection of off-the-beaten path openings!