Jerome Gambit: Stockfish vs Mittens (Part 4)

                                              

[continued from the previous post]

Stockfish  - Mittens bot

Chess.com, 2026

In the battle of the chess engines, the fish has an advantage over the cat.

49...Re8 50.Rxe8+ Bxe8 

Exchanging Rooks decreases White's chances of direct attack on the enemy King, but Stockfish has seen further

51.Rc8 Kf8 52.f6 

Aye, there's the rub.

52...gxf6 53.g7+ Kxg7 54.Rxe8 

Black has a Knight and a pawn (passed) for a Rook, but in this case it is not enough.

54...Kf7 55.Rh8 Kg6 56.Rd8 f5 57.Kb3 Ne4 58.Kxb4 f4 59.c4 Kf5 

The game has reached a fascinating position. 

Black can sacrifice his Knight for White's c-pawn, as in the game, and hope to advance his f-pawn, according to the saying Black pawns move faster in the endgame.

Or he can run that pawn immediately, with 59...f3  but White's King and Rook prove to be better partners than Black's King and Knight, i.e. 60.c5 f2 61.Rd1 Kf7 62.c6 Ke7 63.c7 Nd6 64.Kc5 Nb7+ 65.Kb6 Nd6 66.Kc6 Nc8 67.Rf1 Na7+ 68.Kb7 Nb5 69.Rxf2 Nxc7 70.Kxc7 White will win Black's remaining pawn, and promote his own - or, in some cases, sacrifice his last pawn to trap Black's King on the h-file, eventually producing a side file (as opposed to back rank) mate. 

It is worth playing out. 

60.c5 Nxc5 Black resigned

White has a checkmate in 18 moves, and even Stockfish 16.1 (64 ply) can see it. 

Apparently, so can the Mittens bot.

My thanks to Chessinator for sharing this game.

Jerome Gambit: Stockfish vs Mittens (Part 3)

 

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Stockfish  - Mittens bot

Chess.com, 2026

30...Ne2 

If your opponent attacks a piece, you may not have to move it. Instead, attack one of his pieces of equal or greater value.

The Mittens bot follows this sage advice, but it would have done better to just give up the exchange with 30...Rac8 31.Nxe8 Rxe8, still with an edge. 

31.Rf3 Nd4 32.Re3 b4 

Pursuing the pawn storm, judging that moving either Rook would be a waste of time, as the remaining Rook could still be captured. 

33.e5 

White has time for this.

33...dxe5 34.Nxa8 Rxa8 35.Rxe5 Rc8 

Black has two pieces for a Rook and a pawn. The game is roughly even.

36.Rf1 a5 37.b3 Nb5 38.g5 a4 39.g6 Be8 40.Rfe1 Nc3+ 41.Kc1 Bb5 42.bxa4 Bxa4 43.Kb2 Bc6 

The storms have largely passed.

It is difficult to see that this game began as a Jerome Gambit, although Black's King remains more threatened than White's.

44.a3 Rf8 45.axb4 cxb4 

White will redeploy its Rooks, to no great advantage.

46.Ra1 Ba4 47.Rc5 h5 48.Re1

48...Rb8 

It is not readily apparent that this is a mistake, but  Stockfish 17.1, sitting safely on the sidelines, offers a wild way to keep things balanced, with some interesting interplay between Rook and Bishop: 48...Rd8 49.Rc4 Rb8 50.Re7 Nd5 51.Rb7 Rd8 52.Rd4 Bc6 53.Rb6 Ba8 54.Rb5 Bc6 55.Rc5 Bb7 56.Kc1 Ba8 57.Kd2 Bb7 58.Rc7 Ba8 59.Ra7 Bc6 60.Ra6 Bb7 61.Rb6 Ba8 62.Kc1 Rc8 63.Rd6 Kf8 64.Rd7

If you say so.

49.Re7 

White threatens to double Rooks on the 7th rank. Its pawn on g6 also introduces some back rank mate themes.

Black can distract with Knight checks, but it is not enough.

[to be continued]

Jerome Gambit: Stockfish vs Mittens (Part 2)

[continued from the previous post]

I would like to examine the recent Stockfish - Mittens bot Jerome Gambit game, played well above my own skill level; but, in my defense, I quote a relevant John Heywood from 1546:

A cat maie looke on a kyng.

So we shall be looking at a cat's King, as it were.

In effect, Stockfish, the higher rated chess engine, is giving Mittens "Jerome Gambit odds".

Stockfish  - Mittens bot

Chess.com, 2026

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

I would be surprised (and delighted) if the Jerome Gambit were actually in Stockfish's opening moves "book".

It is more likely the position was set up, as part of the match.

4...Kxf7 5.Nxe5+ Nxe5 6.d4

At first, Alonzo Wheeler Jerome preferred 6.d4 in his games, but he later switched to 6.Qh5+.

Stockfish 16.1 (30) ply prefers 6.Qh5+ by about 1/4 pawn.

6...Bxd4 7.Qxd4 d6 8.Nc3 Nf6 9.Bg5 h6 10.Bh4 Re8 

11.O-O-O Ng6 12. Bg3 Qe7 13.f4 Kg8 

White has castled Queenside. Black has castled-by-hand.

The computer evaluates Black as about 2 1/2 pawns better.

The Database does not have much advice, here, as there is only one game that reaches this position - a 39-move draw.

14.f5 Ne5 15.Bh4 Qf7 16.Bxf6 Qxf6 17.Rhf1 Bd7 

18.Nd5 Qg5+ 19.Kb1 c5 20.Qc3 Bb5 21.Rf4 Be2 22.Re1 Bc4 

Initiating skirmishes.

23.h4 Qd8 24.Ne3 b5 25.Rh1 Qf6 26.Qd2 Bf7 27.g4 Nc6 

28.Nd5 Qd4 29.Qxd4 Nxd4 30.Nc7 

White's Knight fork is a clear threat to gain material. Still, Black is better.

Now come pawn storms on both sides.

[to be continued]

Jerome Gambit: Stockfish vs Mittens (Part 1)

My Google.com Alert, set to find all things Jerome Gambit, just found the YouTube video (on Chessinator's website )

"Stockfish Sacrifices Everything! | Jerome Gambit vs Mittens #chess #gothamchess #chesscom #chessgame"

with the following description

In this game, Stockfish (White) plays the aggressive Jerome Gambit against Mittens (Black). The Jerome Gambit is a wild opening where White sacrifices multiple pieces early to launch a dangerous attack on the king. But can such a risky gambit work against a strong engine like Mittens? Watch the full game to see how the attack unfolds!

The game score does not give the version of Stockfish in the game (most recently released is Stockfish 18), nor does it give the rating of either player, or the time control they performed under. 

Checking the Stockfish website, it appears that the current rating of the program is around 3550.

Likewise, searching for information about the Mittens bot suggests that it is rated around 3000.

Oh - Mittens and I have crossed swords before. See "Jerome Gambit: Cat-Astrophe" for our 22-move game.

[to be continued]

Jerome Gambit: Fingerprints

The following blitz game has Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3Bc4 Bc5 4.Bxf7+) fingerprints all over it.

Alfil-de-Oro - chipichipichapachapa

5 0 blitz, lichess.org, 2026

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.O-O Nf6 5.Bxf7+ 

Temporarily transposing into a "modern" variation of the Jerome Gambit - one without the "classical" Nxe5+.

5...Kxf7 6.Nxe5+ Nxe5 7.d4 

Transposing to more "classical" lines.

7...Bd6 

Alfil-de-Oro has also faced the stronger 7...d5, i.e. 8.dxe5 Nxe4 9.Be3 Qe7 10.Nc3 Nxc3 11.bxc3 c6 12.Bd4 Be6 13.f4 Rhf8 14.f5 Bc8 15.f6 Qe6 Black resigned, Alfil-de-Oro - itsfungus, 5 0 blitz, lichess.org, 2024. 

Much more often he has faced 7...Bxd4 - in 170 games, scoring 53%.

8.dxe5 Bxe5 9.f4 Bd6 10.e5 Bc5+ 11.Kh1 Ne8 

Black's Knight has been driven from the field, but that is not all.

12.Qd5+ Kf8 13.Qxc5+ Qe7 

Against 13...d6 he has scored 2 - 1, with a timeout loss (the clock ran down when he had a checkmate in 7) Alfil-de-Oro - lguoterry, 5 0  blitz, lichess.org, 2024 (0-1, 30); and a couple of wins in Alfil-de-Oro - MEFTUN0666, 5 0 blitz, lichess.org, 2024 (1-0, 32) and Alfil-de-Oro - Thisisaddictive, 5 0 blitz, lichess.org, 2025 (1-0, 18). 

14.Qc3 d6 15.Be3 dxe5 16.fxe5+ Kg8 

Avoiding having his Queen skewered to his King with 17.Bc5.

17.Bc5 

Black resigned

It turns out that even after his King moves, the Black Queen is skewered - to the f8 square, where White's Rook threatens to arrive to deliver checkmate.

So, Black must give up his Knight with 17...Nd6 18.exd6 cxd6 if he wants to keep in the game - a piece down.

He declines.

Jerome Gambit Endgame (Not)

 

I recently played a game that was enjoyable, and which suggested that I had been paying attention to my chess books over the years. 

The following position arose (not out of a Jerome Gambit, although that does not matter, here) after Black's 37th move.

What I could remember from Reuben Fine's Basic Chess Endgames (1941) is that it is good to have a Rook against a Knight in the ending, because the Rook can be exchanged for the Knight...

Not sure I got that right.

Anyhow.

38.Qc3 Qxc3 39.bxc3 

The doubled c-pawns will prove handy.

39...Kg6 40.Rh1 Kg5 41.Kf3 b6 42.Rb1 Nf7 43.axb6 cxb6 44.Rxb6 Ne5+ 

45.Kf2 f3 46.Rxa6 Kf4 47.Rxd6 Kxe4 48.Re6 Kxd5 

49.Rxe5+ Kxe5 50.Kxf3 Kd5 

I am not sure, but my opponent might have been testing me here: I have been known to not pay close enough attention to important things.

51.Ke3 Kc4 52.Kd2 Kc5 53.Kd3 Kd5 54.c4+ Kc5 55.Kc3 

Readers who anticipated this position likely know how the game will end.

55...Kc6 56.Kd4 Kd6 57.c5+ Kc6 58.Kc4 

And so it goes.

58...Kc7 59.Kd5 Kd7 60.c6+ Kc7 61.Kc5 

And, again.

61...Kc8 62.Kd6 Kd8 63.c7+ Kc8 

Here, with 64.Kc6, I would have rewarded my opponent's hopes with stalemate!

64.c3 Black resigned

Now, Black's King will have to release the blockade of the forward c-pawn with 64...Kb7, when my King can advance with 65.Kd7, preparing for the pawn's promotion on the next move.

Jerome Gambit: He Really Knows What He Is Doing

The value of experience in chess can not be over-stated, as the following game demonstrates.

angelcamina - Aleyev-Iliya5953

1 0 bullet, lichess.org, 2026

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Bc5 5.Bxf7+ 

The Italian Four Knights Jerome Gambit

5...Kxf7 6.Nxe5+ Nxe5 7.d4 Bxd4 8.Qxd4 

Of course, the computer still likes Black, but White has his standard plan of castling and then playing f2-f4 - not to mention that The Database has over 1,500 (!) of angelcamina's Jerome Gambit bullet games, so he really knows what he is doing.

8...Nc6 9.Qc4+ Kf8 

This royal side-step is okay, but 9...d5 is stronger.

One step down the slippery slope. 

10.O-O d6 11.f4 Qe712.e5 dxe5 13.fxe5 

13...Qxe5 

Or 13...Nxe5, as in angelcamina - MucTepXyeBlbU, lichess.org, 2025: 14.Qb3 Nc6 15.Bg5 Qc5+ 16.Kh1 Qxg5 17.Ne4 Qe5 18.Nxf6 gxf6 19.Rae1 Qd6 20.Rd1 Qe6 21.Qa3+ Qe7 22.Qc3 Be6 23.Rxf6+ Ke8 24.Re1 Nd8 25.h4 c6 26.h5 Kd7 27.Qe5 Qd6 28.Qg5 Kc7 29.Qg7+ Qd7 30.Qxh8 b6 31.Rf8 Kb7 32.Re8 Qxe8 33.Qxe8 Bd7 White resigned

14.Bf4 

When in doubt, attack the enemy Queen.

Remember: at this time control, a 30-move game means you have 2 seconds thinking time per move; a 20-move game means you have 3 seconds thinking time per move.

14...Qh5 

You attack my piece, I attack your piece would have been a good guide, here.

Instead, Black swings his Queen to the Kingside, hoping to move on the enemy King; but White does the same against Black's King.

15.Rae1 Bf5 

Still swinging. The quiet 15...Qf7 was for choice. 

16.Nd5 

Avoiding the mess: 16.Bxc7 Qf7 17.Qc5+ Kg8 18.Rxf5 Qxc7 19.Nd5 Qf7 20.Ne7+ Nxe7 21.Rxe7 (which would actually be a better choice)

16...Ng4 

It was time for some defense (and an even game) with 16...Rd8, i.e.17.Qc5+ Kf7 18.Nxf6 gxf6 19.Bxc7 Rde8 20.Rxe8 Rxe8 21.Qxf5 Qxf5 22.Rxf5 Nd4  

Aggression often pays off in bullet chess, but not this time.

Now, a couple of scary moves by Black - and then White's pieces finish things.

17.h3 g5 18.Bg3 Na5 19.Rxf5+ Kg7 20.Qxc7+ Kh6 21.hxg4 Qxg4 22.Re6+ Kh5 23.Qf7 checkmate