Jerome Gambit: Counting Up the Numbers (Part 2)

In the previous post (see "Jerome Gambit: Counting Up the Numbers [Part 1]") we looked at the massive collection of games at the lichess.org site and saw how some Jerome Gambit lines - accepted and declined - fared in club level play.

What does the computer engine Stockfish 16.1 think of all of this?

Well, for starters, in evaluating 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ it does not place 4.Bxf7+ in the top 25 fourth-move choices for White.   

Further, at 36 ply depth of evaluation, it sees 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ as about 2 3/4 pawn better for Black.

(New Readers, please do not panic. The Jerome Gambit is considered by masters to be disreputable - if still fun to play in certain circumstances. Club players count on the considerable "shock and awe" chaos it engenders to even the odds.) 

White is happier if the Bishop is not accepted, as 4...Kf8 is about 4 3/4 pawns better for him than 4...Kxf7, and 4...Ke7 is about 5 1/4 pawns better for him than 4...Kxf7  (31 ply).

Clearly the Jerome Gambit accepted lines are the ones that give the first player the greatest challenge.

At 36 ply, the popular 5.Nxe5+ is rated as about 3 pawns better for Black, as opposed to 5.O-O, which is rated as about 3 1/8 pawns better for Black.

Interestingly, 5.b4 is rated as about 3 1/3 pawns better for Black, while 5.Nc3 and 5.a3 are rated slightly even more favorable for the second player.

5.d4 is assessed as about 3 1/2 pawns better for Black, as is 5.c3. 

Apparently, according to the computer, White should smile if his Bishop is declined, and bear down if it is not, putting his effort into 5.Nxe5+, although 5.O-O, 5.b4, 5.Nc3, 5.a3, 5.d4 and 5.c3 are are not evaluated as much worse for him.

Clearly the Evans Jerome Gambit - 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Kxf7 5.b4 - needs another look; as does the counter-intuitive 5.a3, first mentioned in September 2008's "A Closer Look (Part I)" and in the games panga74 - vlad-tepes, GameKnot.com, 2008 (1-0, 16) and (1-0, 31).

It is also worth mentioning "More Russian Home Cooking" from a dozen years ago, where Yury V. Bukayev noted

I have the following new present for you! It's my discovery! 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Nc3 h6 5.a3 (White has the auxiliary threat: 6.b4.) 5...Nd4? 6.Bf7!! White has a very strong attack! (6.Ne5?! Qg5!-+; after 6.Na4 or 6.b4 black can play 6...Bd6! without fast white's winning.) If you agree, you may call it as "Bukayev GP Jerome counter gambit", where "GP" is the well-known words: "giuoco piano".