Saturday, September 12, 2020

Jerome Gambit: Very Complicated and Dangerous

Bert gif


In the following Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) game, play enters the very complicated and dangerous (for both players) historical "His Nibs" variation. Only when Black overlooks a few things can White take control of the game, and take the full point. The notes only touch on a few of the difficulties.

For the  origin story of the line, see "Repairing A Variation (Part 2)"


Boris - NN

2020 


1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 

7.Qf5+ Kd6 8.f4 Qh4+ 

Sometimes Black plays this move to weaken the White Kingside, before retreating his Queen to f6.

9.g3 

9...Nf3+ 

Black's counter attack is very strong. I have had my own troubles with the line (see "Jerome Gambit: Against the Titans"), and my record of 16 - 3 is a bit misleading.

Stockfish 11 shows the tiniest preference (about 1/4 pawn) at 30 ply for this move over 9...Qf6. 

10.Kd1 

The first big decision. His Majesty enters A Dangerous Place.

The Database has 26 games with 10...Kd1; White scores 65%. The Database has 19 games with 10...Kf1; White scores 74%. (Don't bother with 10...Ke2. White has scored 1 - 9 - 1 - 14% - with the move, according to The Database. See "Jerome Gambit: Amusement".)

Both Komodo 10 and Stockfish 11 clearly favor 10.Kf1. How does that fit with the practical results reflected in The Database? As always, the player more comfortable and more familiar with Jerome Gambit positions tends to do better, despite "objective" measurements.

10...Ne7 


Another developing move. For a long time I was convinced that this was the strongest continuation, although lately the computer engines have been pushing 10...Qh6 as even stronger. (The Database shows two games, with White scoring 50%).

11.e5+

White goes after the King. The computer engines suggest that he sigh deeply and give up on the idea of rescuing his Queen, settling for 11.Qxc5+ Kxc5 12.gxh4 with Black clearly for choice. 

11...Kc6 

The only move.

12.Qe4+ d5 

13.exd6+ 

Boris noted

Here my opponent was shocked, spent much time and lost his confidence - he was waiting for Qxf3 to execute a totally crushing move Bg4!!!, but he completely forgot the possibility of en-passant. 

Black has only one move that keeps the advantage, and he doesn't find it.

13...Kxd6 

Through the fog he had to see 13...Nd5 14.gxh4 Bg4, with the advantage, for example 15.c4 Ng5+ 16.Kc2 Nxe4 17.cxd5+ Kxd6 and White's extra pawns are too weak, while Black's development (and extra piece) likely give him a winning advantage.

14.gxh4 Bg4 


The position still looks very scary for White, but he has a new response that keeps Black's advantage small.

15.f5 Nxh2+ 16.Ke1 Nf3+ 


Rescuing the Knight, with check, looks reasonable, but this is where the complications overwhelm Black. He needed to find 16...Nxf5 17.Rxh2 Rae8 18.d3 Rxe4+ 19.dxe4 Nd4 when his lead in development counts more than White's material advantage of the exchange.

17.Kf1 Bxf5 18.Qxf3 Rhf8 19.Ke1 Rae8 


White's Queen is facing two Bishops, a Knight and two Rooks. Boris gives the proper perspective, though

Funny position - he seems to have two horrific discoveries, however there are no good attacks with the knight and lightsquared bishop, so I just smiled and made a room for my bishop, also taking e4 away from his bishop. 

20.d3 

If you are not chuckling at this move, you have not been paying attention. Boris has ice water in his veins.

20...h6 

Stockfish 11 worries that Black has allowed the game to slip away. White's Queen-for-Knight material advantage is now the most important factor.

21.Nc3 a6 22.Bf4+ Kd7 23. Kd2 Kc8 


Black's King is safe, but so is White's.

24.Rae1 Bb4 25.a3 Bxc3+ 26.bxc3 Rf6 27.Rhg1 Bg6 

28.Re2

Boris effectively described the situation

Black has no useful move. 

28...Kb8 29.Re3

Boris, again

At first I wanted to double rooks and win his knight, but now I realised that a rook-queen battery is better, because I can give up my bishop for his bishop with an invasion on the 7-th rank. 

29...Kc8 30.Qe2 Rxf4 31.Rxe7 Black resigned

Whew! That was quite a game. Great win, Boris!


Friday, September 11, 2020

Jerome Gambit: Under Pressure


The following game is a good example of the pressure that White can inflict upon the enemy King in a Jerome-related line. 


Boris - NN

2020

1.e4 e5 2.Nf3 Nc6 3.Bc4 Na5 


In this side line, Black immediately moves to win "the minor exchange" after 4.Bb3 Nxb3.

White can now grab a pawn with 4.Nxe5 Nxc4 5.Nxc4, but he prefers the "Jerome treatment".

4.Bxf7+ Kxf7 5.Nxe5+ Ke6 

A bit stronger might be 5...Ke7. See "Revision".

6.Qh5 


This is very Jerome-like play: first the Bishop is sacrificed, then the Queen goes to h5. The result is a very dynamic position. 

It is worth looking at the alternatives, however, as, surprisingly the fussy Komodo 10 rates other moves higher. Slightly.

First, it is important to mention that The Database has 87 games with 6.Qh5, with White scoring 68%, so it's a good move from a practical point of view, even if the computer evaluates it as -/=.

What does Komodo 10 prefer?

It's favorite (at 25 ply) is 6.d4, which it evaluates as +/=. The Database has 476 games with that move, with White scoring 73%. Fair enough.

The next in preference is 6.Nc3, evaluated as =. The Database has only 1 game, with White scoring 100%. Practically a novelty, or worthy of "Jerome Gambit Secrets #14"

Then comes 6.Qg4+, also evaluated as =. The Database has 55 games, with White scoring 64%.

Following is 6.Nf3, rated as =. The Database has 11 games, with White scoring 82%

Next is 6.0-0, evaluated as =. The Database has 2 games, with White scoring 100%. Again, practically worthy of "Jerome Gambit Secrets #15".

Rated as -/=, with 17 games in The Database, is 6.f4, although it scores 71%.

One way of deciding is to ask yourself, Do you want to sacrifice the Knight at e5? If Yes, you should look at 6.Nc3, 6.Qg4+ and 6.0-0. If No, you should look at 6.d4, 6.Nf3, 6.f4 or 6.Qh5.

It is very important to note that Komodo 10 (like The Database) is only an assistant in making a move choice. The difference in evaluation between its favorite, and the text move, is only about 1 pawn.

6...b5

This is a bit of a surprise, and justifies White's move. Strongest was probably 6...Nf6.

7.Qf5+ Ke7 8.Qf7+ Kd6 

9.Qd5+ Ke7 10.d4 

Capturing the Rook was possible, but White is looking to capture the King. 

10...c6 11.Bg5+ Nf6 12.Qf7+ Kd6 13.Bd2 Nb7 

14.a4 

Looking to add his Rook to the attack. Also possible was the material grab, 14.Ng6 Kc7 15.Nxh8 as 14...hxg6 would be answered by 15.Bf4#.

14...Qe8 

Looking to evict or exchange the Queen. Safer was to withdraw his King with 14...Kc7.

15.axb5 Nd8 

More of the same. His position is a mess. For example, if 15...cxb5, 16.Qxe8 Nxe8 17.Nf7+ will lead to the win of the Rook.

16.Bb4+ Kc7 17.Ba5+ Kb8 18.Qb3

Still focused on the King. He could be temporarily bought off by exchanging Queens on e8, then capturing the Knight on d8, but he wants more.

18...Nb7 19.bxc6 dxc6 20.Nd2 Bd6 

21.Ndc4 Bxe5 22.Nxe5 Nxe4 23.O-O Bd7 

Black still has a  piece for a couple of pawns, but the pressure on his King is intense.

24.Rfe1 Ned6 25.Bb4 Kc8 26.Ra6 h5 


If this is the start of a counter-attack, it is a bit optimistic.

27.Nxc6 Qf7 28.Qg3 Rh6 29.d5 h4 


30.Qc3 Bxc6 31.Rxc6+ Kb8 32.Bxd6+ Nxd6 33.Qb4+ Nb7 

34.Re7 Qxd5 35.Qxb7 checkmate



Thursday, September 10, 2020

Jerome Gambit: Center Action

Here we have 3 more Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) games sent by Boris, from Kazakhstan.

Boris - NN,

2020


1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 

7.f4 Qf6 8.Rf1 g6 9.Qh3+ Kd6 


This move blocks the pawn, which blocks the Bishop, which locks in the Rook... Possibly 9...Ke7 was better.

Interestingly, 9...Kd6 was the choice of Fritz 7, Deep Fritz 8 and Comet B46 in their compter vs computer games, all over a decade ago; while 9...Ke7 was the choice of jmchess, Hiarcs9, Deep Sjeng 1.5, Fritz 5.32, Abrok, Amyan, BBchess and Crafty in their games, mostly more recently.

10.fxe5+ 

The alternative, 10.d4, was seen in a later game by Boris, when, after 10...Bxd4 11.fxe5+ Bxe5 12.Rxf6+ (1-0, 30) he was able to strike back after his first Jerome Gambit loss (see below). 

10...Qxe5 11.d4 

Relying on the threat Bc1-f4.

The alternative, 11.d3, was a start of a very difficult game: 11...Kc6 12.Nc3 d6 13.Qh4 Be6 14.Bf4 Qg7 15.O-O-O Bd4 16.Bd2 h6 17.Kb1 Ne7 18.Qe1 Kd7 19.h3 Rhf8 20.Rh1 b6 21.Bc1 a6 22.Ne2 Bf2 23.Qd2 h5 24.Rdf1 Qe5 25.Nc3 Qc5 26.Rh2 Be3 27.Qe2 Bg1 28.Rxf8 Rxf8 29.Rh1 Nc6 30.Qe1 Bf2 31.Qe2 Bd4 32.Rf1 Rxf1 33.Qxf1 Bxc3 34.bxc3 Qxc3 35.a3 Nd4 White resigned, Boris' first Jerome Gambit loss.

All this center action with White's King stuck in the middle is unsettling. Perhaps 11.Nc3 was to be considered as well.

11...Qxe4+ 12.Qe3 Qxd4 13. Qe2 Qh4+ 14.Kd1 Qd4+ 

Wow. Was Black suggesting a draw by repetition?

15.Bd2 b6 

Even though Black is a piece and a pawn ahead, Komodo 10 rates the position as even. The open long diagonals put Black's Rooks at rish. 

16.c3 Qa4+ 17.b3 Qh4 18.g3 Qe7 

I am not sure what Black hoped to accomplish with his Queen moves, but he has radically altered the position.

19.Qg2 

Simple enough.

19...c6 20.Bf4+ Ke6 21.Qe2+ Kf7 22.Bd6+ 

23...Qf6 23.Rxf6+ Kxf6 24.Qe5+ Black resigned



Wednesday, September 9, 2020

Jerome Gambit: GM vs GM, Upset Again

The following online Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) blitz game is another interesting grandmaster vs grandmaster affair between Hikaru Nakamura and Peter Michalik

It is educational to see how much a grandmaster observes (and overlooks) in a 3-minute game played for fun. After all, given the gift of a couple of pieces, all Black has to do is survive, while White has to win.

(Following the old English proverb "A cat may look at a king", I have added some notes, but - of course - they are heavily assisted by the computer.)


SanitationEngineer - Lunaticx

3 0 blitz, Chess.com, 2020.


1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 


4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Kf8 

7.Qxe5 d6 8.Qg3 Nf6 9.d3 Kf7 

The game continues the same way as the one posted yesterday. Surely, Black has no reason to vary.

10.b3 

White intends to fianchetto his Bishop, instead of exchanging it on e3 as in the previous game. Komodo 10 mildly disagrees.

10...Bd4 11.c3 Bb6 12.Bb2 Rf8 


Black plans to castle-by-hand.

White's Bishop is one move away from owning a long diagonal.

13.c4 

Suddenly, Komodo 10 rates Black the equivalant of a Queen ahead, preferring 13.0-0. Can you see why? 

13...Kg8 

Consistent, safe, and preserving his advantage. However, he missed 13...Nh5, which would put his opponent's Queen in grave danger. 

14.O-O 

The Queen needed to run to safer ground with 14.Qh4.

14...Ng4 


 Grandmasters don't see everything, but they usually see enough.

15.d4 Qf6 16.e5 dxe5 17.c5 Ba5 

18.a3 

Working with the "Jerome pawns" to trap or win the enemy Bishop. He would have done himself a favor by playing his next move, first, i.e. 18.h3 Nh6 and then 19.b4, since 19...Bxb4 20.Qb3+ Be6 21.Qxb4 would win the piece. Please note that 18.b4 right away would not work as well, since after 18...Bxb4 19.Qb3+ Be6 20.Qxb4, 20...Qh4 would be crushing.

18...c6 19.h3 Nh6 

20.dxe5 Qf7 21.b4 Bc7 22.Nd2 Bf5 23.Rac1 Rad8 24.Nc4 

24...Bd3 25.Nd6 Bxd6 26.cxd6 Bxf1 27.e6 Qg6 28.Qxg6 hxg6 29.e7 Bd3 30.exf8=Q+ Kxf8 


After a flurry of tactics, Black has a few weaknesses to attack.

31.Bd4 Kf7 32.Bxa7 Rxd6 33.g4 Ng8 

34.f3 Nf6 35.Kf2 Bb5 36.Ra1 Rd2+ 37.Kg3 Ba4 38.Bc5 Rd3 39.Kf2 Bd1 


Black's pieces are now cooperating, and things are looking grim for White. Will the clock become a factor? 

40.f4  Ne4+ 41.Ke1 Ba4 42.Bg1 Rxh3 43.Kf1 Rf3+ 44.Ke2 Rg3 45.Re1 Bc2 46.Be3 Rxg4 

47.Rc1 Ba4 48.Kf3 Nf6 49.Bd4 Rh4 50.Be5 Bb3 51.Kg3 Rg4+ 52.Kf2 Bd5 

53.b5 Rg2+ 54.Ke3 Rg3+ 55.Kd4 Rxa3 56.Kc5 Rb3 57.bxc6 bxc6 58.Kd6 


(Note to self: Rook and Knight vs Rook is usually a draw - if there are no pawns.)

58...Ne4+ 59.Kc7 Ke6 60.Bxg7 c5 61.Rg1

Black's advantage is too large.

61...Rb7+ 62.Kd8 c4 

He had a pretty checkmate with 62...Rd7+ 63.Kc8 Nd6+ 64.Kb8 Rb7+ 65.Ka8 Rb6+ 66.Ka7 Nc8# but there are a number of ways to win.  

63.Bd4 Kf5 64.Ra1 Be6 65.Ra5+ Kxf4 66.Be5+ Kf3 67.Ra3+ c3 68.Bxc3 

Still fighting.

68...Rd7+ 69.Ke8 Nd6+ 70.Kf8 Rf7+ 71.Kg8 Ra7+ 72.Kf8 Rxa3 73.Bb4 Rd3 74.Ke7 Ne4 75.Kxe6 g5 White resigned


A solid win for GM Michalik, against stubborn defense by GM Nakamura.