Jerome Gambit for Dummies 2.0 (Part 3)

                                            

[continued from the previous post]

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

It is worth starting off with a quote from the post"The Spectre of the Jerome Gambit (Part 1)"

For most club players, it is easier to attack than defend; and that works in the Jerome Gambit's favor, as its whole idea is attack. 

The essence of a gambit is that White (in this case) gives up material for something. We refer to the Jerome Gambit, not the Jerome Blunder (although some might prefer that name, and the editor of the American Chess Journal referred to it in 1877 as "Jerome's Absurdity"). The defender struggles to make sense out of an opening that isn't familiar - but White wouldn't sacrifice pieces for nothing, would he? 

Also, most club players have been exposed to "Checkmate in X moves" problems, but they have rarely faced "Black to move and escape the mating net" challenges. They learn how to attack, but they also learn that a King out in the open is one that will perish. 

So, being attacked can be unsettling, and for a club player it may very well lead to a distracted or diminished mental state. 

All of which addresses the point that sometimes the Jerome Gambit wins when it "objectively" shouldn't. 

Although 98% of the time (according to The Database) Black captures the Bishop, the move is not forced. It is simply a choice for the second player between having an "objectively" winning game with 4...Kxf7 and having the worse position after 4...Kf8 or 4...Ke7.

Jerome Gambit Declined

Jerome Gambit Declined

Yet a few defenders will adopt the sly attitude If he wants me to take the Bishop, then I won't take it.

There is some "psychology" in this, too: the Jerome Gambiteer suddenly finds himself "stuck" with a calm, but "objectively" better game than had been expected a move before. This change of fortune can take some getting used to.

For this reason, even though it is an unlikely event, for peace of mind White might want to prepare a response to the Jerome Gambit Declined.

In the first place, White can feel reassured when facing the Gambit Declined. The Database has 471 games with 4...Kf8 with White scoring 61%; and 59 games with 4...Ke7 with White scoring 70%. Stockfish 14.1 (30 ply) rates White about 3 pawns better in the first case, and about 4 pawns better in the second.

White can respond to the Jerome Gambit Declined with the simple 5.Bb3, knowing that he has invested a couple of tempos to obtain a pawn and prevent Black from castling. (Also possible are 5.Bc4 and 5.Bd5.) The Database shows White with 5.Bb3 scoring 66% against 4...Kf8 and 100% against 4...Ke7.

White can part with his Bishop, instead, with 5.Bxg8, scoring 63% against 4...Kf8 and 91% against 4...Ke7. (Personally, I like to keep the Bishop.)

Some players seeking greater complications have left the Bishop in place and tried 5.Nxe5, apparently hoping to continue along orthodox Jerome Gambit lines, gaining a tempo when Black finally plays ...Kxf7. White has been successful with 5.Nxe5 over-the-board (The Database has 68 games, White scores 60%) even though the computer frowns upon the move, seeing Black about 1 3/4 pawns better. (It must be noted that the tries 4...Kf8/4...Ke7 5.Nxe5 Nxe5 6.Qh5 d6 and 4...Kf8/4...Ke7 5.Nxe5 Nxe5 6.d4 Nxf7 are not very encouraging for White.)

Of course, there is also the rare 5.Qe2 with the idea of Qc4+ to then capture the enemy Bishop at c5, and 5.b4, to transpose to a sort of Evans Jerome Gambit declined. Although each line leads to an advantage for White, it is not necessary to be this creative.

4...Kxf7

Jerome Gambit Accepted

We finally arrive at the second Critical Position.

The "classical" Jerome Gambit continues with 5.Nxe5 (about 60% of the games in my database that start 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Kxf7) while "modern" Jerome Gambits (not played by Jerome and his contemporaries, mostly internet games) continue with alternatives such as 5.Nc3, 5.d3, or 5.0-0. 

Thirteen years ago, in "Jerome Gambit for Dummies (2)" I wrote

For the record, after a very long think (over 12 hours) Deep Rybka 3.0 Aquarium assesses Black as being 1.91 pawns better after 5.Nxe5+ as well as after 5.Nc3. It sees White being only 1.72 pawns worse after 5.d3 or 5.0-0.

One fifth of a pawn doesn't seem like a lot to me, and I still prefer the complications of 5.Nxe5+. Jerome Gambiteers who feel they can knuckle down and simply outplay their opponents with the "modern" variations are free to disagree with me.

Computer chess engines have improved mightily since 2009, and now Stockfish 14.1 (30 ply) rates 5.Nxe5+ as a little more than 4 pawns better for Black, as opposed to 5.Nc3 (about 5 3/4 pawns better for Black) 5.d3 (a bit more than 6 pawns better for Black) and 5.0-0 (about 4 3/4 pawns better for Black).

So, today the computer says Play 5.Nxe5+, but If you don't want to sacrifice a second piece, play 5.0-0.

[to be continued]