Saturday, April 3, 2021

Jerome Gambit: Borrowed


Readers of this blog continue to share games that they have played where they have "borrowed" the Jerome Gambit's idea of Bxf7+ and had success in the attack on the enemy King that followed. Who am I to object??


marcopuc91 - danielhenriqueslopes

3 0 blitz, Chess.com, 2021


1.e4 e5 2.Nf3 Bc5 

Interesting. Knowingly or otherwise, Black offers the Bush-Gass Gambit.  See "Worth A Second Look..." Part 1, 2 and 3.

3.Bc4 Nf6 

Now we have the Petroff Defense, Italian Variation. Check out the early "Not Quite the Jerome Gambit"

4.Bxf7+ 



4...Kxf7 5. Nxe5+ Ke8 6.d4 Bb4+ 7.c3 Bd6 


It was a better idea to retreat the Bishop to e7, but Black is thinking aggressively.

8.O-O Bxe5 9.Bg5 

Very tricky. Is it unsound? Many "unsound" ideas are sound in a 3-minute game.

9...Bd6 


The messy way out for Black was 9... h6 10.Bh4 Bf4 11.e5 g5 12.Bg3 Ng8 13.c4 Kf7 14.Qf3 d6 15.Bxf4 gxf4 16.Qxf4+ Kg7 17.Nc3 Qg5 when his 2 extra pieces - and a possible Queen exchange - would help.

10.e5 Bxe5 

Stockfish 13 suggests that Black "allow" White to force the draw with 10...Be7 11.exf6 Bxf6 12.Re1+ Kf8 13.Bxf6 gxf6 14.Qh5 Nc6 15.Re3 Rg8 16.Qxh7 d6 17.Qh6+ Kf7 18.Qh5+ Rg6 19.Qh7+ Rg7 20.Qh5+ Kf8 21.Qh8+ Rg8 etc. I don't think either player would go along with that.

11.dxe5 Rf8 

Black is right, the pressure on his Knight is difficult, but there is no way out at this point. 

12.Re1 Nc6 13.exf6+ Ne7 


Black's pieces are trying to help, but it's really all over. 

14.Qh5+ g6 15.Qxh7 d6 16.fxe7 Qd7 17.exf8=Q+ Kxf8 18.Bh6+ Black resigned






Friday, April 2, 2021

Jerome Gambit: Artificial Wha?



Sometimes a chess computer program can act as an interesting model of a human chess player.

Lately, in part because of my interest in the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) and my interest in the notion of "errors in thinking", I have been exploring ways to make a chess computer program dumber

I have done this before: see "Artificial Stupidity" and "Artificial Ignorance (Part 1)".

I mean, I have already learned from chess programs some ideas on how to play chess smarter, like

-give myself a reasonable amount of thinking time per move;

-increase the number of choices that I consider each time I get ready to move, not just look at the "obvious" one; and

-force myself to look one or two ply deeper than I would normally, when evaluating alternatives    

Conversely, if I want my chess computer program to be less smart, I could decrease the available "thinking" time per move, decrease the number of search nodes for each move, or decrease the search ply depth.

One of the more interesting ideas I found in an internet discussion was to have the computer chess engine vary how often it plays what it has calculated as the "best" move, versus playing alternatives it saw as less strong. For example, it could consider any move it evaluated as anywhere near (a pawn's difference, a piece's difference, etc.) the top move as equally playable as the "best". Or, the engine could be set to play the "best" move a certain percentage of the time, and a random move the rest of the time.

Much of this thinking was spurred by the following game.

At the time, I was bored, but not too bored; I wanted a challenge, but not too much of a challenge; I was ready to go to sleep, but not quite ready. 

So I turned to the Chess Titans chess program (for an earlier example see "Contempt?!"), which was set to the Beginner level.


Rick - Chess Titans

beginner level, casual game, 2021

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


Of course, the Jerome Gambit. I probably would have just turned the thing off if it had wanted to play the Nadjorf Sicilian.

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ 


6...Ke6 7. Qf5+ Kd6 8. f4 Qh4+ 


Wow! The computer is interested in playing the very sharp "Nibs" variation. That has to be part of its "book".

Funny thing, this has happed before, but I forgot about it. See "Jerome Gambit: Against the Titans (Part 1)"

9.g3 c6 10.Qxe5 checkmate


Well... uh... okay.

I suspect that many chess computer programs would have found 9...Nf3+, instead, and that others would have opted for 9...Qf6.

Quite possibly Chess Titans went for a random suggestion, instead of the best, on move 9.

(The Database points out that 3 of my earlier games - blitz, against human opponents - continued 9...Nf3+ 10.Kd1 Qe7 11.Qd5#. Ahem.)

Thursday, April 1, 2021

Jerome Gambit: Sometimes Enlightenment Does Not Come (Part 2)

 


[continued from the previous post]

perrypawnpusher - DaniyarManat

1 day/move, Chess.com, 2021


I suddenly realized that my d-pawn was pinned, and that Black could grab my Knight with 15...Qxe5. But - he didn't! 

What had I missed? What had he missed?

Although it was too late - a bad habit, mulling over missed moves while the game is still in session, but I at least had the benefit of the time control being a day per move - I was able to reassure myself that 15...Qxe5 could have been met by 16.f6!?, threatening to deliver checkmate, capture the Knight on e7, or advance the pawn to f7 with a fork of the enemy King and Rook.  After 16...Ng6 17. f7+ Kh8 18.fxe8=Q+ Rxe8 I would have been up the exchange and a pawn.

I was not sure if my opponent had missed 15...Qxe5 like I had, or if he saw the move and its repercussions and so avoided it. After the game was finished, I checked and Stockfish 13's recommendation was that 15...Qxe5. Sigh.

15...Rad8 

Completing his development and putting further pressure on the White pawn center.

I was agog after the game to see that the computer evaluated me at this point as being more than a Queen ahead. This was somewhat explained by its recommendation 16.Kh1 (breaking the pin) Kf8 (huh?) 17.Bg5 Ng8 (huh?) 18.Bxf6 Nxf6. I would have thought Black's best after 16.Kh1 was 16...Bxd4 17.cxd4 Rxd4, being only a piece down, but Stockfish 13 disagrees and suggested a very elaborate series of moves, some of them threats to the Queen, that are hard to fathom.

16.Be3 

Breaking the pin on the d-pawn. This much I still understand.

16...Rd6 

I had expected 16...Rf8, and was not really sure how to respond. Let me get back to you on that...

In the meantime, the text move and the next give the opportunity for some tempo moves. 

17.Nc4 Rd7 18.e5 Qf8 19.f6 Black resigned


The Rook on d7 is threatened, along with the Knight at e7. 19...Rd5 would fall to the 20.f7+ fork and subsequent promotion.

I think my opponent played well in this game, except for his slip on move 12. I would give more feedback, but the play was rather complicated, and the insights of my silicon analyst helper were too much over my head. 



Wednesday, March 31, 2021

Jerome Gambit: Sometimes Enlightenment Does Not Come (Part 1)



When I finish a complicated game of chess I am often happy to turn it over to one of my silicon friends - nowadays, Stockfish 13 - to help me understand more about what was going on in the play, and how things could have been improved.

Sometimes, however, enlightenment does not come.

Take the following game. I am happy to share what I was thinking about, and I am willing to explain what I can about what was happening, but my computer friend let me down, with analyses that I too often could make no sense of at all. (That is part of the reason that I have linked to so many of my earlier games.)

Here we go.


perrypawnpusher - DaniyarManat

1 day/move, Chess.com, 2021


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


 4...Kxf7 5.Nxe5+ Kf8 

This move was mentioned in Alonzo Wheeler Jerome's first published analysis of his gambit in the April 1874 issue of the Dubuque Chess Journal. Black is not interested in gathering in more sacrificed material and keeps his King relatively safe.

6.Nxc6 dxc6 


Preventing White's d2-d4, and thus stronger than 6...bxc6 as in perrypawnpusher - badhorsey, blitz, FICS, 2011 (1-0, 26). 

7.O-O 

Or 7.d3 as in perrypawnpusher - fortytwooz, blitz, FICS, 2010 (1-0, 29); perrypawnpusher - Jore, blitz, FICS, 2011 (0-1, 16)perrypawnpusher - Conspicuous, blitz, FICS, 2011 (1-0, 13)perrypawnpusher -Lark, blitz, FICS, 2011 (1-0, 12); and perrypawnpusher - pitrisko, blitz, FICS, 2011, (0-1, 30).

Also 7.Nc3 as in perrypawnpusher - Ykcir, blitz, FICS, 2009(1/2 - 1/2, 11). 

7...Qf6 

Black puts pressure on the two long dark diagonals.

I have also faced

7...Bd6 in perrypawnpusher - Lark, blitz, FICS, 2009 (1-0, 18) 

7...Be6 in perrypawnpusher - CorH, blitz, FICS, 2009 (0-1, 74); perrypawnpusher - spince, blitz, FICS, 2013 (1-0); perrypawnpusher - PasayDefence, "Piano Piano" tournament, Chess.com, 2020 (1/2-1/2, 57); 

7...Ne7, in perrypawnpusher - smarlny, blitz, FICS, 2011,(1-0, 25); and 

7...Qh4 in perrypawnpusher - pitrisko, blitz, FICS, 2011 (0-1, 30) and perrypawnpusher - Al-der,"Italian Game Classic", Chess.com, 2019 (1-0, 26)

8.c3 

This was something new for me, but building a Jerome pawn center was not.

8...Ne7  9.d4 Bb6 

The Bishop's pin on White's d-pawn will weigh heavily in the play to come.

10.Nd2 Kf7 11.f4 Rf8 12.Nf3


White's broad pawn center just about balances out Black's material advantage, although the open lines for his two Bishops have to be attended to.

After the game Stockfish 13 rated the position as equal, and recommended instead of the text move, 12.a4 (I am not sure why) a5 13.f5 Kg8 (finishing castling-by-hand) 14.Nc4 Nxf5 (returning material) 15.exf5 Bxf5.

12...Bg4 

This is a tactical oversight. My first thought was to reply 13.h3 and to follow 13...Bxf3 14.Qxf3 with 15.g4 and some serious pawn action on the Kingside. After the game Stockfish 13 suggested that it was not impressed, giving 14...c5 as a counter that gave Black a clear advantage. Maybe it is my club player perspective, but it looks like 15.d5 then would leave White okay.

Anyhow, a second look - drawn by the fact that Black has only partly castled-by-hand -  gave me the correct response.

13.Ne5+  Kg8 14.Qxg4 Rfe8 15.f5 


15...Rad8 

This move threw me into a panic. Had I missed something? Had my opponent, in turn, missed something? Suddenly there seemed to be a lot more going on than my planned 16.Bg5.


[to be continued]

Tuesday, March 30, 2021

Jerome Gambit: Bullet

Bullet games amaze me. I am amazed that people can think that fast. By comparison, I am sure that my first and last bullet game would go something like this: 1.e4 e5 2.Nf3 Bc5 3.Bc4 Nc6 4.Bxf7+ White loses on time.

The following game by longtime Jerome Gambiteer angelcamina has a good bit of lightness imbedded in it, so it is essential to keep in mind that it is one of those 1-minute, no increment games that rewards aggressive play, even if the attack is not always the most efficient one.


angelcamina - Dr_Hik

1 0 bullet, lichess.org, 2021


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


4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 7.f4 Nf7 


Interesting. This solid move - returning material but leaving Black with an edge - is not often played, but it appeared in a game just a few posts ago, as well.

8.Qf5+ 

Which piece to protect? Black chooses to hang onto the Bishop, but this kind of decision making takes time - a rare comodity in a 1-minute bullet game.

8...Kd6 9.Qd5+ 

Pretty funny. White could have simply grabbed the Knight with 9.Qxf7.

9...Ke7 10.Qxc5+ d6 11.Qe3 Nf6 


12.O-O Re8 13.d4 Kf8 14.e5 dxe5 15.fxe5 Nd5 


16.Qe4 c6 

A slip. Dropping a pawn in bullet is not immediately lethal, but it can cause a distraction.

17.Qxh7 Qe7 

Wow. I was not expecting that.

Neither was White.

18.b3 Be6 

Okay, this is getting silly.

19.Ba3 

The second deadliest move on the board.

19...Nb4

Yes, but... 

20.c3 Nc2 

Okay.

21.Bxe7+ Kxe7 


The checkmate threat has disappeared, at the cost of a Queen.

White now finishes his development, and has enough of a material edge to end the game with a strong attack.

22.Nd2 

I know, but losing the exchange is not longer a big deal.

11...Nxa1 23.Rxa1 Rg8 24.Rf1 Bd5 25.c4 Be6 26.Ne4 g6 27.Nd6 c5 28.Nxf7 Bxf7 29.Rxf7+ Black resigned




Monday, March 29, 2021

The Story of the Jerome Gambit



The Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) is a school for tactics. Ideally, the players discover all of the moves during the game, but often they have to be uncovered and appreciated afterward.

If you are a tactical wizard, there is room for the Jerome Gambit in your opening repertoire. If you are becoming a tactical wizard, the story is the same.

The following game has tactics galore. White had his chances, as did Black, and both, as Maxwell Smart used to say, "Missed by that much."

With all the notes, I mean no disrespect to either player. There is much to learn from this game. It is a fact of blitz that there was little time to find everything.


lksharma - garciadeveas

3 0 blitz, FICS, 2021

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.d4 

White is willing to offer more material to open another line of attack. In a 3-minute game, this is more playable - lksharma has played it 40 times before this game.

5...Nxd4 

I suppose that Black avoided 5...Bxd4 to avoid 6.Nxd4 (winning Bishop for Knight) or 6.c3 (kicking the Bishop with tempo) but it was the better move. The text unprotects the pawn at e5.

6.Nxe5+ Kf8 7.Qh5 


Simply going for checkmate.

7...g6 

This is the story of Jerome Gambit: Black has a defense, but he has to find it. With 7...Qe7 he could have secured his position.

8.Nxg6+ hxg6 9.Qxh8 

The Rook capture looked attractive, but White could have simplied things - to his advantage - with 9.Qxc5+ d6 10.Qxd4, cleaning up the counter-attackers.

It is possible that White chose his move based on the belief that the upcoming Black Knight fork would be unsuccessful.

9...Nxc2+ 10.Kf1 

The King seeks shelter, but he was needed to help on the Queenside: 10.Kd1 Nxa1 11.Bh6+ Kf7 12.Qg7+ Ke6 13.Qxg6+ Nf6 14.Bg7 d6 15.Nc3 When White is better, even if he is down a couple of pieces!

10...Qf6 11.Bh6+ 

Development with check. This is an idea to remember.

11...Kf7

Black returns the favor with a King's misstep of his own. The proper move was 11...Ke7. What difference does it make? It means that when White checks with his Queen, Black's Queen can interpose. An exchange of Queens would squash White's attack, and Black's King would no longer be in danger - while the material advantage would make Black better.  

12.Qh7+ Ke6 13.Qxg8+ 


Now Black has two reasonable choices.

He can interpose his Queen, and after 13...Qf7 14.Qxf7+ Kxf7 15.Ke2 Nxe1 16.Rc1 b6 17.Nc3 Bb7 18.Rxa1 White would be a pawn up, but Black would have the two Bishops.

Of course, if a draw is okay for Black, he can simply play 13...Ke7, when White's best choice is probably 14.Qh7+ Ke8 15.Qg8+ etc. with a draw by repetition. A messier draw - or a prettier one, depending on how you look at it - would be 14.Ke1 Nxa1 15.Nc3 Qxf2+ 16.Kd1 Qc2+ 17.Ke1 Qf2+ etc.

Instead, Black looks at all that he has going on - the capture of the Rook at a1 and the Queen check at f2 - and steps into danger. 

13...Kd6

Missing the fact that White now has the same kind of clean up move mentioned in the note to move 9.

14.f4 

Very much a Jerome Gambit move. The threatened pawn fork of the enemy King and Queen is attractive.

Still, it was okay to go for a simpler win with 14.Qd5+ Ke7 15.Qxc5+ Ke8 16.Qxc2  or the related 14.Bf8+ Kc6 15.Qd5+ Kb6 16.Bxc5+ Ka6 17.Qd3+ b5 18.Qxc2.

14...Ne3+ 

Black has one last attacking idea. He has to keep checking to keep things going.

15.Ke2 Qxb2+ 16.Kf3 

Tragic. With 16.Nd2 there was safety. 

16...Qxg2 checkmate 


Wow.

Sunday, March 28, 2021

Jerome Gambit: Always Educational



I ran across a video the other day featuring FM Noam Aviv Vitenberg playing the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+). It is a fun game and a fun video. (Be sure to check it out!)  His comments reflect the thinking of a higher level player, which is always educational.


FUTUREWCC - Abject_Pawn

7 3 blitz, lichess.org, 2020


1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 


4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ng6 



It was tantalizing to hear the master say, as a casual aside, that he had played a game that went 6...g6 7.Qxe5 Qe7 7.Qxh8 Qxe4, but that was all he shared. I will try to track that one down.

7.Qd5+ 

The FM's comment here is interesting, "Maybe this check doesn't do anything good. I don't know."

Many Jerome Gambit players play the Queen "nudge" here - about 40%, according to The Database - as opposed to the direct capture of the Bishop. But why?

With 7.Qd5+ White takes a move to chase the Black King back to the back rank, where it can interfere with the development of his Rook at h8. If Black wants his Rook to go to e8, or if he wants to castle-by-hand, he will have to return the tempo at some point by playing ...Kf7.

Does this really matter? Probably not to a computer. But not all club players defending against the Jerome realize the value of getting the King out of the way. This shows up in The Database, where 7.Qxc5 scores 46%, while 7.Qd5+ scores 70%.

It is possible that 7.Qd5+ is played more often those more familiar or comfortable with the Jerome Gambit. There may be more to it than that, though. 

The ChessBase statistics function, when applied to The Database, indicates that the average rating of those that play 7.Qxc5 is about even with those who defend against the move, so a score near 50% is to be expected. Maybe the 46% shows a little underperforming by White. 

However, the function (again looking at The Database) shows that those who play 7.Qxc5+ are on the average about 55 points higher than those they face, predicting that they would score 58%. As we have seen, though, they overperform, scoring 70%.

Interesting... Remember, as ever, YMMV.

7...Ke8 8.Qxc5 d6 9.Qe3 Nf6 10.d4 Kf7 


As predicted in the note above.

11.O-O Re8 12.Nc3 Kg8 13.f4 

"Very risky move". He pointed out that his opponent now had 13...Nxe4 14.Nxe4 d5, although the move played "is also a decent move." We are talking about a casual game, streamed, with a lot of converstation between moves, so it's not a big deal, as we shall see.

13...Bf5 14.e5 Ng4


"I don't understand, to be honest. Ah, 15.Qg3, I guess my opponent has the idea of going 15...Qh4 in that case, insuring that I trade off Queens." Giving his opponent the benefit of the doubt; some defenders just like attacking the Queen.

15.Qe2 dxe5 16.dxe5 Qd4+ 17.Kh1 

17...N6xe5 

"Very interesting move here by my opponent here, going for the kill." The FM thinks it through, though, and finds a line where he thinks he might be "surviving".

18.fxe5 Rxe5 19.Qf3 Rf8 20.Bf4 


White has reached a position that is about even, a reasonable result from playing a "refuted" opening. Things are still complicated, however, and when Black decides to attack the Queen another way - well, there is a reason that masters are masters, starting with tactical ability. 

20... Be4 

Simplest would have been the retreat 20...Ree8. Now simplification will show Black the error of his ways.

21.Bxe5 Nf2+ 22.Rxf2 Qxf2 23.Qxf2 Rxf2 24.Nxe4 Re2 25.Bxc7 Rxe4 26.c3 Black resigned


White is up a piece and a pawn.