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

Jerome Gambit: Unfinished Symphony (Part 1)

The following game, my most recent Jerome Gambit from an ongoing Chess.com tournament, was an adventure from start to finish. The adventure was shorter than I expected, however. It is filled out with related games played at a number of different online sites, all from The Database.

perrypawnpusher - Nivaethan2000
Giuoco Piano Thematic Tournament, Chess.com 2016

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

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

This is a popular line, but it is the first time that I have played it. I have preferred 7.Qf5+, and am something like 59 - 10 with the move. That's a score of almost 86% - why take the risk of something new? As I mentioned in a previous post, I need to keep learning about the Jerome Gambit.

White's King is going to be insecure for a while, and if he castles, it will be Queenside.

7...Qf6 8.Rf1 g6

This pawn kick is understandable, but Knight moves also have been played.

For example, 8... Ne7 was seen in Wall,B - Asterisk engine, Palm Bay, FL, 2015 (1-0, 39).

Also 8...Nh6 9.Nc3 c6 10.fxe5 Qxe5 11.Qh4 Rf8 12.Rxf8 Bxf8 13.d3 Bb4 14.Bd2 Qf6 15.Qh5 d6 16.Qe8+ Qe7 17.Qh8 g5 18.h4 g4 19.Bxh6 Bxc3+ 20.bxc3 Qxh4+ 21.Ke2 Kd7 22.Rf1 Kc7 23.Rf7+ Kb6 24.Qd4+ Ka6 25.Qa4+ Kb6 26.Be3+ c5 27.Qb3+ Kc6 28.Qd5+ Kb5 29.Rxb7+ Black resigned, tapirus - mrdenetop, Chess.com, 2011.

There was the creative 8...Nd3+ as in MrJoker - Melbourne, Internet Chess Club 2011 (1-0, 29). 

9.Qh3+ Ke7

Again, this is not the only move (although it foreshadows the theme of play along the dark squares).

Examples of games with the novel way of returning the piece, 9...Ng4, are mrjoker - jmt, Internet Chess Club, 2008 (1-0, 29);  Wall,B - Guest3164644, PlayChess.com 2013 (1-0, 20); and Wall,B - Betarsolta, PlayChess.com, 2015 (1-0, 12). 

The imprudent 9...Kf7 was seen in Wall,B - Guest1690223, PlayChess.com, 2012 (1-0, 12).

The alternative 9...Kd6 has been met several ways: 

10.fxe5+ Qxe5 11.d3 (11.Nc3!?) Kc6 12.Nc3 d6 13.Qf3 Be6 14.Bf4 Qh5 15.g4 Bxg4 16.Qh1 Bb4 17.e5+ Kb6 18.Qg1+ Ka6 19.Qd4 Bxc3+ 20.bxc3 Nh6 21.Qa4+ Kb6 22.Rb1+ Black disconnected and forfeited, MrJoker - Melbourne, Internet Chess Club, 2011; 

10.Qg3 Nf7 (best is 10...Nd3+) 11.e5+ Nxe5 12.Nc3 Ke6 13.Ne4 Nf3+ 14.Qxf3 Qh4+ 15.g3 Qe7 16.f5+ Kd5 17.Kd1 Qxe4 18.c4+ Ke5 19.Re1 d5 20.Rxe4+ dxe4 21.d4+ Bxd4 22.Qf4+ Kf6 23.fxg6+ Kxg6 24.Qg5+ Kf7 25.Qd5+ Be6 26.Qxd4 Nf6 27.Ke1 Rhf8 28.Qe5 Rac8 29.Bg5 Kg6 30.Bd2 Bf5 31.Qf4 e3 32.Bxe3 Rce8 33.Ke2 Bg4+ 34.Kd3 Rd8+ 35.Kc2 Bf5+ 36.Kb3 Rd3+ 37.Kb4 a5+ 38.Kxa5 b6+ 39.Kb4 c5+ 40.Kb5 Bd7+ 41.Kxb6 Nd5+ 42.cxd5 Rxf4 43.Bxf4 Rxd5 44.Rc1 Be6 45.b3 Kf5 46.Kc6 Kf6 47.Rc2 Rf5 48.Bc1 Bd5+ 49.Kd6 Ba8 50.Bb2+ Kg6 51.Be5 Rf8 52.Rxc5 Rf2 53.a4 Rxh2 54.b4 Ra2 55.a5 Bh1 56.Bc3 Rg2 57.b5 Rxg3 58.b6 Rd3+ 59.Kc7 Re3 60.a6 Re7+ 61.Kd6 Rf7 62.Rc6 Black resigned, Zappa 1.1 - Deep Fritz 8, Blitz:5, 2006.

10.b4!? Nf3+ (if 10...Bxb4 11.Qb3; best is 10...Bd4) 11.Qxf3 Qxa1 12.bxc5+ Ke7 13.Qb3 Nf6 14.Bb2 Qxb1+ 15.Ke2 Qxf1+ 16.Kxf1 Rf8 17.Qg3 Ke8 18.f5 Rf7 19.Qe5+ Kf8 20.Qxc7 Ne8 21.Qe5 gxf5 22.exf5 b6 23.Ba3 d6 24.Qh8+ Ke7 25.cxd6+ Kd8 26.g4 Be6 27.Ke1 Bxa2 28.Qa1 Bd5 29.Qd4 Bh1 30.Qc4 Rd7 31.Qg8 a6 32.g5 a5 33.c4 Rg7 34.Qe6 Raa7 35.d7 Raxd7 36.Qxb6+ Kc8 37.f6 Rgf7 38.Qxa5 Nc7 39.Qe5 Bb7 40.d4 Bg2 41.Kf2 Bc6 42.d5 Bxd5 43.cxd5 Rxd5 44.Qf4 Rdd7 45.Bb4 Kb7 46.Qc4 Nd5 47.Qb5+ Kc7 48.Bc5 Kc8 49.Qa6+ Kb8 50.Bd6+ Nc7 51.h3 Rd8 52.Qb5+ Kc8 53.Bxc7 Rxc7 54.Qf5+ Kb7 55.f7 Rcc8 56.Qxh7 Kc6 57.Qe4+ Kd6 58.Qd4+ Kc7 59.Qf4+ Black resigned, Junior 7 - Fritz 7, Utrecht, 2002; 

10.Nc3 (best) Kc6 11.Nd5 d6 12.Qg3 Qe6 13.fxe5 Qxe5 14.Qxe5 dxe5 15.b4 Bd6 16.Bb2 Ne7 17.c4 b6 18.Rc1 Nxd5 19.exd5+ Kd7 20.c5 bxc5 21.bxc5 Be7 22.Bxe5 Rf8 23.c6+ Kd8 24.Rxf8+ Bxf8 25.Rc3 Be7 26.Re3 h5 27.Bxc7+ Kxc7 28.Rxe7+ Kd6 29.Re8 Kxd5 30.Rg8 Bb7 31.Rxg6 Re8+ 32.Kf2 Bxc6 33.Rh6 Re5 34.d4 Rf5+ 35.Ke3 Rg5 36.g3 a5 37.a3 Bb5 38.Rh7 Kc4 39.Rf7 Kb3 40.Kf4 Rd5 41.Ke4 Be8 42.Kxd5 Bxf7+ 43.Ke5 Kxa3 44.d5 a4 45.d6 Be8 46.Kf6 Kb4 47.Ke7 Bb5 48.d7 Bxd7 49.Kxd7 a3 50.Ke6 a2 51.Kf5 a1=Q 52.Kg5 Qe5+ 53.Kh4 White resigned, DrunkenMaster 1.2 - Comet B48, Torneo tematico GaJero00-A, 2009

10.Nc3 

A little bit better might be 10.fxe5 Qxe5 although it did not make a difference in GeniusPawn - jmchess, FICS, 2000 which continued with 11.Nc3, anyway: 11...Nf6 12.d4 Bxd4 13.Bf4 Bxc3+ 14.bxc3 Qxe4+ 15.Kd1 d6 16.Qh4 Kf7 17.Kc1 Bf5 18.Qf2 Qc4 19.Rb1 Ne4 20.Qe3 Qxf1+ 21.Kb2 Qxg2 22.Bh6 Qxh2 23.Ka1 Qxc2 24.Rc1 Qa4 25.Qd3 Rae8 26.Qd5+ Be6 27.Rf1+ Ke7 28.Bg5+ Kd7 29.Rf7+ Kc8 White resigned.

The question is, can Black respond to 10.Nc3 by making the White capture of the Knight on e5 more difficult, if not impossible? The answer, as we shall see, is both yes and no

[to be continued]

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 1½ 11 11 11 11.5/14
2 WB Nimzo 2000b       00 ** 01 11 1½ 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 0½ 00 01 ** 1½ 01 11 6.5/14
6 DrunkenMaster 1.2 00 00 00 10 0½ ** 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

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 1½ 11 11 11 11.5/14
2 WB Nimzo 2000b       00 ** 01 11 1½ 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 0½ 00 01 ** 1½ 01 11 6.5/14
6 DrunkenMaster 1.2 00 00 00 10 0½ ** 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