Jerome Gambit: When It Looks So Easy

Sometimes the Jerome Gambit looks so easy to play. I know that it's not - but, sometimes...

Wall, Bill - Minaevm
lichess.org, 2017

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb4+ 7.c3 Bxc3+ 8.Nxc3 Nc4 

9.Qh5+ g6 10.Qd5+ Kf8 11.Qxc4 Ne7 12.Bh6+ Ke8 13.Nb5 c6
14.Nd6 checkmate

Jerome Gambit: Winging It

With attacks on both wings, the following game is an interesting example of who "gets there the firstest with the mostest".

The final position is very impressive, and bears close examination.

Wall, Bill - Facundo
lichess.org, 2017 

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 

6...Bxd4 7.Qxd4 d6 8.Nc3 Nf6 9.f3 Re8 

It looks like Bill wants to hold the center with f2-f3 and castle Queenside. He does - but that also leaves him open to start a pawn storm on the Kingside.

10.Bf4 Nc6 11.Qf2 Be6 12.O-O-O Qe7 13.h4 a5 

Black likes the idea, too.

14.h5 h6 15.g4 a4 16.g5 hxg5 17.Bxg5 a3 18.b3 Bd7 19.h6 g6 

Hoping to close things down on the Kingside, but the move overlooks play in the center. Stockfish 8 suggests 19...Qe5 20.Qd2 Rh8, although White can maintain play, it suggests, with 21.Rhe1 gxh6 22.f4 Nxe4 23.fxe5 Nxd2 24.Bxd2 Nxe5 and a drawn ending with Bishops-of-opposite-colors is one possibility.

20.Nd5 Qe5 21.Bxf6 Black resigned

A rather impressive position: Black's Queen is dominated by White's Knight and Bishop!

Her Majesty can escape attack with 21...Qe6, but then 22.h7!? follows. Black can offer the exchange with 22...Rh8, but White has no interest in the material, and can play 23.Qg3!? with the idea of Rh6, attacking the Black g-pawn, to follow. The defense of the pawn with 23...Ne7 simply drops a piece to 24.Bxe7, and the "counter-attack" 24...Qe5 25.Qh4 Qb2+ is an illusion, as after 26.Kd2 Qd4+ 27.Ke2 White's King is safe, and Black's will come under attack again.

Jerome Gambit: Winning is Not Annoying

Chessfriend Vlasta Fejfar of the Czech Republic has faced the "annoying defense" to the Jerome Gambit a number of times. In the following game, his most recent, he comes away with the whole point.

Vlastous - Idalgit
Internet, 2017

 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

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

This is also called the "silicon defense" because it is the choice of many computer chess programs. Black returns a piece and takes a lot of the action out of the position.

8.fxe5 dxe5 9.Qh3+ Kf7 

The text is about equal to 9...Ke7 which was seen in Fejfar,V -Goc,P, 2015 (1/2 - 1/2, 70),  Fejfar,V - Chvojka, correspondence, 2016 (0-1, 32) and Vlastous - irinat, Chessmaniac, 2016 (0-1, 38). 

10.Qh5+ Ke6 11.Qe2 

Stockfish 8 gives the practical suggestion 11.Qh3+ hoping for a draw by repetition. 

11...Qd6

Instead, 11...Ke7 was successful for Black in Wall,B - Alfil engine, Palm Bay, FL 2015 (0-1, 23); while 11...Nf6 was seen in Shredder 8 - RevvedUp, blitz 2 12, 2006 (1-0, 25) and RevvedUp - Yace Paderborn, blitz2 12, 2006 (0-1, 14).

12.Nc3 c6 13.Na4 Nf6 

A tactical slip that drops a piece. Black may have unconsciously decided that his opponent has finished moving his Queen.

14.Qc4+ Ke7 15.Nxc5 b6 16.Nd3 a5 17.Qc3 Ke6 

 

18.Qb3+ Black resigned

Perhaps a bit soon, but Black sees he will lose the b-pawn, and White's Queen will escape any danger, so the game may have lost its interest.

Jerome Gambit Discovery

I enjoyed looking at positions in the Jerome Gambit with the help of Stockfish 8 - to the depth of 30 ply - that I thought I would look at a few of the classical defenses and see what turns up.

My first surprise came in Blackburne's Defense.
 
dj222 - invincible1
GameKnot.com, 2003

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

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ g6 7.Qxe5 d6

Blackburne's Defense. It is a complicated, tactical mess. Initially thought to favor Black, and then to favor White, the current assessment has been that it leads to a complicated draw that either player avoids at his own peril. But, maybe it favors White after all.

8.Qxh8 Qh4 9.d4

See "Traps and Zaps" for some background. The move was suggested in the notes to Amateur - Blackburne, London, 1885, but given scant attention afterward. 

Far more often played is 9.0-0. Although White won in Chandler - Dimitrov, 2004, analysis supported a complicated drawn game.

9...Nf6

Black ignores the danger his Bishop is in. Only one game in The Database has this move, which is Stockfish 8's top choce.

It is hard for Black not to plump for 9...Qxe4+ 10.Be3 Qxg2 with complications, but the text is the second player's best option.

Check out "Opening Traps by GM Ferzbery" for a look.

10.Nd2

White does not go after the enemy Bishop, but keeps White's Queen away from e4.

10...Bxd4 11.Rf1

It was probably best to play 11.0-0 here, and ride out the storm after 11...Qxh2+ 12.Kxh2 Ng4+ 13.Kg3 Bxh8, coming out the exchange ahead.

11...Bh3

Recovering a pawn and offering a Rook while threatening White's Queen! Unfortunately, it is a mistake: Black had better in 11...b6 with the idea of 12...Ba6 and a very complicated, but balanced, game.

12.Qxa8 Bxg2 13.Qxb7 Bxf1 14.Qb3+ Ke7 15.Qg3

White's Queen returns in time to save the King.

15...Qxg3 16.hxg3 Bg2 17.f3 Bh3 Black resigned

Stumbling to the Top

My last comment about the Chess.com Giuoco Piano thematic tournament that I most recently played in (see "Unlinked") was a bit melancholy

And - I'm sitting on top of the standings in the Chess.com Giuoco Piano tournament, one point ahead of the field (thanks, in part, to the Jerome Gambit). However, IlToscano has two games left, so he can catch and pass me... 

Surprisingly, once again (see "An Unexpected Success") the competition was fierce enough amongst other players that it turns out that nobody will be able to catch me after all (there are a couple of games not yet finished).

Another inexplicable first place finish, assisted by a 7-2 record with the Jerome Gambit.  

Jerome Gambit: Synthesis

What can we make of the last two posts (see "Jerome Gambit: What Are the Odds?" and "Jerome Gambit: Stockfish 8 Checks In"), each of which provides useful information about the Jerome Gambit?

First, we need to recall Geoff Chandler's very useful and very practical chart.

Here is a one-move blunder table showing how severe the blunder needs to be in a game between two players of the same grade.

All players should be able to spot their opponent leaving a mate in one on.
A 1200 player should win if an opponent blunders a Queen or a Rook. But not necessarily if they pick up a Bishop or Knight.
1500 players often convert piece-up games into a win, but this is not the case if a pawn or two up.
An 1800 player usually wins if they are two pawns up.
In a game between two 2000+ players a blundered pawn is usually enough to win.

This chart immediately addresses a couple of questions:

Q: Why do masters not play the Jerome Gambit?
A: According to Chandler, a pawn advantage is enough for a master to win the game. In the Jerome, White sacrifices one or two pieces, and Stockfish 8 evaluates the position with 4.Bxf7+ as giving Black a 1.85 pawn advantage. That would be self-injurious in a master vs master game.

Q: So why is it that, according to The Database, White scores 45% after 4.Bxf7+ ?
A: Recall that The Database contains primarily club-level games played on the internet. We can see from Chandler's chart that players rated 1200 and 1500 often need more than "almost two pawns" to win. Even an 1800 rated player only "usually" wins when two pawns up - and the Jerome Gambit sacrifices 1.85. The errors of the Jerome Gambit fit right in with the errors of club play.

What else?

Both practice and computer analysis (as well as common sense) strongly suggest that Black should accept the Bishop after 4.Bxf7+. To refuse it is to give White a better (but not necessarily winning) game.

Black should also accept the Knight after 5.Nxe5+ (Stockfish 8's top choice for White here, at 30 ply search; although it rates almost as good 5.0-0, 5.c3, 5.d3, 5.Qe2 and 5.Nc3.) Best play is for the defender to be brave, but that does not always come easy for club players.

Practical play and computer analysis suggest that White garners further risk in playing the Italian Four Knights Jerome Gambit, as opposed to the main line classical variation.

The Database and Stockfish 8 slightly prefer 6.Qh5+ over 6.d4, but only slightly. It is worth being comfortable with both.

Both the Semi-Italian Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.0-0 Bc5 5.Bxf7+) and the Blackburne Shilling Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4 4.Bxf7+) improve White's chances over the main line Jerome Gambit, according to both The Database and Stockfish 8.

Based on practice, Black defends best against 6.Qh5+ with 6...Kf8. Stockfish 8, instead, prefers 6...Ke6. The move 6...g6 - from Blackburne's wonderful crush of the Jerome - scores poorly according to The Database, while Stockfish 8 says it leads Black to an advantage of 1.55 pawns.

The computer's choice of 6...Ke6, which it rates as -2.42, fits in well with computers in general preferring the "annoying defense" (continuing 7.f4 d6) and pushes the defender's advantage to almost 2 1/2 pawns. It may be the complexity of the line, or it may be that it is played by weaker club players, that accounts for being less successful (per The Database) than 6...Kf8 in play. 

Finally: the Jerome Gambit is a light-hearted opening for practicing attack (or defense) and performs best in casual or blitz play, or when White is giving a lesser-rated player "Jerome Gambit" odds. You are not likely to see Magnus Carlsen playing any time soon.

Jerome Gambit: Stockfish 8 Checks In

In the previous post I spent a little time with The Database and came up with some scoring percentages for White for different lines of play in the Jerome Gambit.

I gave two caveats:

All statistics need to be approached cautiously. In this case it is useful to remember that the vast majority of games in The Database are drawn from over a decade of games played online at FICS, regardless of outcome; so they should be somewhat representative of Jerome Gambit play among club players who contest online... 

Of course, were I to subject each of these positions to the scrutiny of, say, Stockfish 8, the computer's evaluation would likely, in some cases, vary significant from the game outcomes in The Database!

Then I decided to give Stockfish 8 a chance, after all.

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5

If the game continues 3...Nd4 4.Bxf7+ instead, Stockfish 8 rates the position at 30 ply depth of search as -.18, about an even game.

4.Bxf7+

Stockfish 8 rates the position as -1.85 at 30 ply depth of search, meaning that Black is not quite 2 pawns better.

If Black plays 4...h6 instead, after 5.0-0 Bc5 6.Bxf7+ Stockfish 8 rates the position as -1.77 at 30 ply search depth. After 5.Nc3 Bc5 6.Bxf7+, it rates the position at 30 ply search depth as -1.45.

4...Kxf7

As for declining the Bishop, Stockfish 8 rates 4...Kf8 at 30 ply depth of search as +1.68, giving White more than a pawn and a half advantage. It rates 4...Ke7 at +2.01, giving White a two pawn advantage.

5.Nxe5+

Stockfish 8 rates this position as -2.41 at 30 ply depth of search. 

If, instead, the game continues 5.Nc3 Nf6, the game reaches the Four Knights variation by transposition. Stockfish 8 rates the position as -2.85 at 30 ply depth of search.

5...Nxe5

Stockfish 8 rates this position as -2.32 at 30 ply depth of search.

If Black replies, instead, 5...Kf8, Stockfish 8 rates the position -.56; if Black replies 5...Ke8 Stockfish 8 rates the position +.22; if Black replies 5...Ke6, Stockfish 8 rates the position +.94; if Black replies 5...Ke7, Stockfish 8 rates the position +1.04; all at 30 ply depth of search.

6.Qh5+

Stockfish 8 rates this position as -2.27 at 30 ply of depth.

If White plays 6.d4 instead, Stockfish 8 rates the position as -2.46 at 30 ply depth.

6...g6

Stockfish 8 rates this position as -1.55 at 30 ply of depth.

It rates 6...Kf8 as -1.75 ; 6...Ke6 as -2.42; and 6...Ke7 as +2.71; all at 30 ply of depth.