In this episode of chess noob Quick Wins, we’re going to have a look back at the lovely von Hennig Gambit by White, against Black’s Caro-Kann Defense (1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Bc4!?). We’d recently covered one line of the von Hennig recently but it’s been two years since I first covered the “famous” 8-move checkmate. I was inspired as earlier in the week, I managed to pull this off again, along with another von Hennig quick win game, which I’ll cover next week!
The wonderful thing about this 8-move checkmate is that every single move by Black appears to be a natural and reasonable move. From the position, the single most common response by Black to the von Hennig Gambit is (4… Nf6), developing a knight to a normal square, and defending their pawn now on e4 from recapture by White’s c3-knight.
White’s next move immediately pressures that e4-pawn with (5. f3), adding as second attacker. Black will likely (and correctly) calculate that it is difficult to defend the pawn. Uncommonly, they might try with (5… Bf5) but as we saw in the aforementioned article and video from a fortnight ago, Black can get aggressively attacked with (6. g4)! The most common response by Black is to capture down the chain (5… exf3), win a second pawn and acknowledge that they’ll will give one back. This nonetheless consolidates the material advantage.
White now captures the pawn with development (6. Nxf3) and we see the logic to the gambit. White has given up a point of material, but Black moved the same pawn three times in the opening, which now evaporates from the board. White gains an excellent relative advantage in development – three pieces developed to natural squares, a pawn in the centre, and reading to castle kingside. Black, on the other hand, has only a single piece developed, no pawns in the centre, and at least three moves away from castling. In this position, Black will be strongly drawn towards developing another minor piece. However, the king’s bishop is stuck behind the d7-pawn, and the queen’s knight’s “natural” square of c6 is occupied by the Caro-Kann pawn. Thus, the most natural piece to move will be the queen’s (light square) bishop and indeed, this piece is the most moved in the position. But to which square? There are only two sensible looking candidate positions; to f5 or to g4. At the beginner-intermediate level, Black will almost certainly be drawn towards playing (6… Bg4) as it seemingly pins White’s f3-knight to the queen! If the goal of the move was to regain tempo, this seems like a very reasonable move!
However, this critical move is a blunder! White now has the audacious (7. Ne5)! It counterattacks Black’s g4-bishop but looks like an “oh no, my queen!” mistake! Did White miss the fact that it was pinned and has now hung their queen?! Of course, this is a trap and much of the success of this trap line is thus in psychological tactics – it comes down to whether White was able to construct a flow such that Black doesn’t suspect, and hence look for the trap! If Black played (6… Bg4??) in the first place, objectively a bad move, the conditional probability is that Black doesn’t already know the line. If Black is unable to resist the allure of the “free” queen and captures (7… Bxd1), then White has the immediate stunning checkmate with (8. Bxf7#)!
So, how often does this happen? One way of analysing this is to look at the Lichess community database, and observe the frequency of choices made by Black from the beginning of the von Hennig Gambit line. For players of all strengths:
- 4… Nf6 59%
- 5… exf3 62%
- 6… Bg4 35%
- 7… Bxd1 30%
Multiplied together, this equates to expecting this exact checkmate win for White in 3.8% of all games from the beginning of the von Hennig Gambit!
For lower-rated players (1600 ELO and lower, limited to blitz and rapid only)…
- 4… Nf6 51%
- 5… exf3 70%
- 6… Bg4 53%
- 7… Bxd1 43%
… which gives an expected rate of just over 8% of all von Hennig Gambit games ending in this checkmate! This is roughly 1 in 12 games against one of the best responses by Black against (1. e4)! Amazing!
Now clearly, the most critical move for White is (7. Ne5) as it is where White ostensibly hangs their queen, thus setting the “oh no, my queen!” trap. There are ways of playing this move to lower the likelihood of Black smelling a rat!
In this game, which 15+10 rapid, in a particular style to fool my opponent. I played the preceding moves relatively quickly, but in the “normal” way of rapid in the opening, which is a move every 1 to 3 seconds. However, as they progressed down the line, I deliberately tried to “blitz” out the moves – for instance, (6. Nxf3) was played in only 0.8 seconds, which would have contrasted with Black’s previously more deliberate calculations: for instance, (4… Nf6) took them 29 seconds, and (5… exf3) took 15 seconds.
The psychological impression that I wanted Black to develop, the belief that I wanted them to construct in their mind was that (i) while they were carefully calculating a position, that (ii) I was only carelessly responding with only a moment’s thought. If they held such a notion, it would be much less likely that they would think that I was setting a trap!
For my critical move (7. Ne5), I was holding onto the knight with my mouse, poised and ready to drop the piece onto e5 should they play (6… Bg4). They did, and I dropped the knight in 0.5 seconds! Consider the likely internal narrative by Black: my bishop pins the knight and I could capture the queen, and then only a moment after the move, with that internal narrative still front of mind, with the developing impression that their opponent is careless, the queen is suddenly available for the capture! Black didn’t hesitate, and captured the poisoned queen in 5.4 seconds, losing the game.
Game: https://www.chess.com/game/live/113226009875
A historical note:
Devious trickery involving an “oh no, my queen!” trap have been played in chess for hundreds of years. Like in my game, these involve a degree of psychological sophistication to pull off successfully, and the best example that I’m aware of is the game by French chess master François Antoine de Légal de Kermeur (1702-1792), master of the famous Café de la Régence, and the best chess player in the world in the early 18th century, where he plays his eponymous line, The Legal Trap: (de Légal — Saint Brie, 1750, Paris France).
In this game, de Légal played not only with rook odds, but also a deliberately unsound bluff to arrive at a checkmate a move earlier! The story might be apocryphal, but it’s too good to not be true!
On move 4, Saint Brie plays (4… Bg4) pinning de Légal’s knight to the queen, a good move. De Légal, pretends to have accidentally touched the knight, pulling his hand back. Saint Brie notices, and gleefully points out the touch move rule. De Légal, trolling Saint Brie, acts to regretfully move the knight (5. Nxe5), and of course the rest is history! Saint Brie, captures the queen, temporarily elated, thinking himself as winning against the best chess player in France. De Légal then shows him why he’s the boss of the Café de la Régence, executing one of the most beautiful checkmate patterns in all of chess!
A second note?!
Interestingly, the critical position in the 8-move checkmate in the von Hennig Gambit after Black plays (6… Bg4??) can be transposed into from two other openings. The first is another gambit by White against the Caro-Kann Defense, the Rasa-Studier Gambit. The second is a transposition from the Blackmar-Diemer Gambit.
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2024.06.27"]
[Round "?"]
[White "vitualis"]
[Black "blunder_commander"]
[Result "1-0"]
[ECO "B15"]
[WhiteElo "1303"]
[BlackElo "1226"]
[TimeControl "900+10"]
[EndTime "4:19:31 PDT"]
[Termination "vitualis won by checkmate"]
[WhiteUrl "https://images.chesscomfiles.com/uploads/v1/user/3711094.f52a0759.100x100o.671ef4f371ed@3x.png"]
[WhiteCountry "17"]
[WhiteTitle ""]
[BlackUrl "https://images.chesscomfiles.com/uploads/v1/user/94111294.a11f1722.100x100o.b1293678c339@3x.jpeg"]
[BlackCountry "112"]
[BlackTitle ""]
1. e4 {[%clk 0:15:10][%timestamp 1]} 1... c6 {[%clk 0:15:09.1][%timestamp 9]} 2.
d4 {[%clk 0:15:16.7][%timestamp 33]} 2... d5 {[%clk 0:15:18.1][%timestamp 10]}
3. Nc3 {[%clk 0:15:25.8][%timestamp 9]} 3... dxe4 {[%clk 0:15:26.6][%timestamp
15]} 4. Bc4 $5 {[%clk 0:15:35.3][%timestamp 5][%c_effect
c4;square;c4;type;Interesting;persistent;true] Caro-Kann Defense: von Hennig
Gambit $1} 4... Nf6 {[%clk 0:15:07.6][%timestamp 290]} 5. f3 {[%clk
0:15:42.9][%timestamp 24]} 5... exf3 {[%clk 0:15:02.6][%timestamp 150]} 6. Nxf3
{[%clk 0:15:52.1][%timestamp 8]} 6... Bg4 $4 {[%clk 0:15:11.3][%timestamp
13][%c_arrow
c8f5;keyPressed;none;from;c8;opacity;0.8;to;f5;persistent;false][%c_highlight
f5;keyPressed;none;opacity;0.8;square;f5;persistent;false,g4;keyPressed;none;opacity;0.8;square;g4;persistent;false][%c_effect
g4;square;g4;type;Blunder;persistent;true] A blunder $1} 7. Ne5 $1 {[%clk
0:16:01.6][%timestamp 5][%c_effect e5;square;e5;type;GreatFind;persistent;true]
Oh no, my queen $1} 7... Bxd1 $4 {[%clk 0:15:15.9][%timestamp 54][%c_effect
d1;square;d1;type;Blunder;persistent;true][%c_highlight
d1;keyPressed;none;opacity;0.8;square;d1;persistent;false,e6;keyPressed;none;opacity;0.8;square;e6;persistent;false][%c_arrow
g4e6;keyPressed;none;from;g4;opacity;0.8;to;e6;persistent;false] Black was
unable to resist the queen sac trap $1} 8. Bxf7# {[%clk 0:16:10.3][%timestamp
13][%c_effect
e1;square;e1;type;Winner,e8;square;e8;type;CheckmateBlack][%c_arrow
e5f7;keyPressed;none;from;e5;opacity;0.8;to;f7;persistent;false,e5d7;keyPressed;none;from;e5;opacity;0.8;to;d7;persistent;false,f7e8;keyPressed;none;from;f7;opacity;0.8;to;e8;persistent;false][%c_highlight
f7;keyPressed;none;opacity;0.8;square;f7;persistent;false,d7;keyPressed;none;opacity;0.8;square;d7;persistent;false,e8;keyPressed;none;opacity;0.8;square;e8;persistent;false]
Checkmate, GG $1} 1-0
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