The Halloween Gambit is Scarier Than You Think

I used to think the Four Knights variation was pretty boring. I mean just look at it. 

But that was before I decided to take on e5. It looks like an implausible sacrifice, dare I say a blunder,  but suspend your disbelief long enough to look at the record of games won and lost (at chessgames.com).

It is hard to take these numbers seriously. Can Nxe5 really win almost twice as often as the main lines? Admittedly the stats here are not so promising but the "blunder" Nxe5 is a lot of fun. It sets up a pawn march stealing tempi against the Black knights, whereafter White's strong center, and the possibility of an immediate clamp on d6, make the Halloweed Gambit one of the most dangerous I have seen. Tim Krabbe wrote a wonderful essay on the topic, further convincing me to give this a shot.

It is hard to ignore the fact that after the innocuous 5... Nc6 White has scored wins in 63% of games with a 6.d5 push. That's because returning the knight to e5 invites 7. f4 and 8. e5 with tempo followed by 9. d6 and White already has a clamp. Nb5 will be strong even if pawns are exchanged (whereas ..a6 can be answered with h4, further harassing the knight). For example after  ..cd 10. ed Qb6 I like 11. Nb5 because it forces .. ..Kd8. 12 f5 then gains yet another tempo and after 13 Bf4 we intend Qd2, O-O-O. Not a winning position by any means but Black is likely to spend a lot more time on the clock than White.

White plays 11. Nb5!? in the 6..Ne5 variation

An unknown (?) beautiful rook sacrifice in the 10 ..Qh4+ line

One should play Nb5 against 10 ..Qh4+ 11. g3 Qf6 as well. Then 12 ..Kd8 is a common response and then13 Be3 b6 is Minchev vs Konev (and several other games) where White invariably plays 14. Nxa7?! which is wrong. Black need not repeat history but can take on d6 with his queen. The analysis below, however, shows that White can force matters with 14. Qd5! and 15. Bh3! sacrificing a rook to trap Black's queen.

I'm not sure if Qd5 is well known so I look forward to springing this over the board. And to summarize, these lines suggest that the 5..Nc6 6..Ne5 7..Ng6 bounce is potentially problematic for Black because it lets White build the f4-e5-d6 pawn phalanx on Black's time. 

Also in the ...Nc6 variation, Black can try giving up the rook on a8 in order to free the game up a bit, as my opponent tried in this game. 

He who runs away lives to fight another ... move or two?!

Now I must mention the double retreat, when Black retreats fully by playing 6..Nb8. This is the ultimate attempt to take the material and run for the hills. I don't think it works. Indeed, it may be possible to justify playing the Halloween Gambit purely for those somewhat rare occasions where Black retreats both his knights to the eighth rank. There is an aesthetic appeal of the resulting position and, more pertinently, possibilities for an immediate win abound.

When Black retreats 6..Nb8 White follows with 7. e5 and the double retreat of Black's knights (i.e. 7..Ng8) allows 8. d6 once again.

White should play 8.d6! in response to  a full retreat of the knights

This time it lands Black with a position that is almost unplayable. For example in Hielscher vs Bartmus Black reacted with 8..f6 and should have lost immediately. Can you see it?

White to play and win

White let the ball go by, unfortunately, going on to lose after the insipid 9. f4. But 9. Qe2! is the winning move that I've been lucky to play a few times.  Preparing ..f6 with 8..c6 doesn't help either. In Brause - Betrueger mentioned by Krabbe, the game continued 9. Bc4 f6. 10. Qh5+ g6 11. ef which is cute and won quickly. And reading this I noticed the delightful 10. Ne5! as well (see position below). The knight is poison, of course, because 11. Qxd5 will win king or queen.

An alternative finish to Brause-Betrueger

Perhaps Black is better off taking on d6 immediately but with Nb5 coming (and White aiming for Bc4, Qe2) Black is totally hamstrung by the blockading pawn. As Krabbe also points out, the natural-looking ..Qf6 leads to an important position after Nb5 Na6.

White has a crushing position

Here despite the material deficit, White has practically won. He plans to castle and then Re1, Qe2 will be deadly. The position is evaluated at +3.50 by the ICC's computer and, since we are letting the computer's have their say, Krabbe notes that a computer program set up especially to play this opening has won 29.5 of 30 games from the position above! It seems that accepting the knight and then running as far away as possible is just a little too simplistic. Here is my most recent game, at the time of writing. 

As the Coen brothers would remind us in No Country For Old Men, there are no clean getaways.

Black plays Ne7

I've also encountered Ne7 once or twice, which is probably just bad. The thing to remember about this opening, however, is that as White you don't always have to go for the jugular. Instead, we just develop normally with the usual plan of bringing the rook to e1 with mating threats at e8. The funny thing about the Halloween Gambit is how easy it is for Black to find himself in something resembling a full board zugzwang. For instance: 

 Black's last move was made because there's nothing else. But after White pushes f3, what does Black do?

Black retreats to b8, and pins with Qe7

A reasonable response for Black

Still, White is okay here with more active play. I suggest Nb5 and then meeting ..Na6 with d6. This requires accurate defense (see diagram below). If Black mistakenly takes on d6 then White will play Nd6+ and has a big edge. He can force weakness with Bg5 provoking ..f6 and ..g5, for example.

Still plenty of fun for White

Black is better off playing ..Qe6 in the position above. In bullet and blitz this is still a fun game for White however, who can take on c7 with the pawn to free the d6 square for his knight. This does allows ..Bb4+ which is considered good for Black, but it isn't much better over the board. As a pragmatic matter, White is less likely to stumble than Black. After the night check on d6 White's bishop aims for c4, f7 is weak and he has the idea of playing b3, Ba3, and castling queenside. If Black plays Bb4+ and retakes on c7, for example, he can easily drift into a position like the following. 

White plays b3, Ba3 and O-O-O

Black is a piece up but here has no chance to survive. I don't mean to imply the variation is winning or even theoretically good for White (in the strictest sense of the minimax algorithm). However, it seems to me that when mere mortals (let's say ~2000) play this kind of position, it is very easy for Black to fall off the ledge or at minimum, spin time on the clock because there are no obvious improving moves. 

The ..d6 "trap" 

The standard refutation begins with 7..d5!

8. Qe2 looks okay against the 7..c6 variation. The d4 pawn can be sacrificed

I think a key question is whether the d4 pawn can be sacrificed with decent play. Kiesler thinks so and mentions 9. Ne4 Qxd4 10 c3 Qb6 (..Qxe5 11. f4!) 11. O-O Nxe5 12. Bf4 is fun for White. But don't take his advice and play 11. Be3 Qa5 12. f4 in this variation because after 12..d5 I don't see how White can justify his deficit.

Black may also employ the strategy 8..Qa5 intending ..b5 ..Na6 which is quite interesting. It is tempting for White to withdraw the white bishop to b3 hoping for tactics against f7. However, as a general rule in this gambit, I personally prefer to try to control f5, which is a key square, rather than aim at f7.

Here Bd3 also means that Black can't play ..Ba6, and his development is still stunted. Meanwhile, White's game plays itself with the pawn roller. Black will probably be giving up material as his Kingside pieces get tangled in each other. Fleeing to the Queenside by casting long helps, but White has such a strong center it is a very pleasant game. 

Black plays ..Bb4 and ..Ne7

There are lots of interesting sidelines, but I want to focus on the ones you'll actually see in practice. A common approach for Black, who of course is trying to untangle his Kingside, is to play Bb4 and Ne7. This is a solid approach and the one I would personally play as Black. It is tempting for White to castle and start the pawn roller with Ne2, f4, and so on, but Black can come out way ahead because f5 is well guarded. There just isn't enough compensation (unless you are playing bullet in which case you might have five to ten seconds on the clock already - which has got to be worth two pawns). 

My general rule, however, is that if Black allows it White should play for Scholar's mate with Qf3. This move tends to help cramp Black's Kingside (and you might even get a pre-move checkmate). In keeping with that theme, White should try to make Black feel that congestion as much as possible. Hence 9 h4! 

Don't be surprised to see Bxc3 here, because Black probably figures it will give him or her more time to think. It is a tricky position for Black to be in. The best move on the board, objectively, is Nh6 but if Black is unfamiliar with the position that looks like it requires some thought. After all, Bxh6 can wreck the Kingside pawns. The resulting position is objectively good for Black but which side would you really rather play? 

You'll probably see this position so let's notice the finesse: White can through in Bg5 first to force f6 and only then take on h6. If White knows this line, Black is walking a tightrope. A sample continuation with good defense might run as follows. 

If you run through this kind of variation you'll arrive at the conclusion that Black is theoretically better. But to get to that assessment, Black needs to avoid numerous opportunities to fall well behind. Furthermore, in a bullet chess, White will get quite a few checks in, and can generate a lot of little threats - each one potentially costing Black critical time on the clock. I regard the Halloween as an excellent "time gambit" for this reason. White's play is more natural than Black's. 

Declining the gambit

There are numerous ways for Black to decline the piece. The obscure book Halloween Gambit - Openings for Chess Hooligans (in Russian) goes into considerable detail and it does pay to book up. I will content myself with a recent game in which I gave my opponent a chance to change his mind. This chewed up a bit of clock, which was helpful. It wasn't my greatest game, but it was good enough. 

 The other thing you'll see a lot is Bb4. You should remember the dance of the Queen from g4 to b4 and back to g4. The position is very strong for White. Our hooligan friend George Renko suggests Bf4 but the computer, and I, like the double clamp with c5. This buys time to bring the rook into play and Black is just crushed. 

After ..d5 rather than Nxc3, keep things simple with Bd3 so you can take the knight on e4. Look for the Queen fork picking up the loose bishop on a5, as with the following line. 

There is also asymmetrical approach for Black, though I have never, ever seen it in a real game. It isn't that bad. Play Qh5 and the symmetry ends! You can choose whether to keep queens on, and it is pleasant for White either way. 

The main line

Finally, we come to the main. Black players who know their theory might play ..d5 8. Bxd5 c6 intending 9.. Bb4 and ..Bxc3 because this has been regarded as the right way to punish the opening. It is certainly a test for White but the first player can play patiently with sustained compensation in the form of a powerful pawn center. Objectively White may be worse here but over the board both 9.Bb3 and 9.Be4 are more than playable, especially in blitz and bullet. 

I prefer to retreat the Bishop to e4 rather than b3 because controlling f5 keeps the pawn roller alive. A great many games will run as follows when both players fight to control that square:

This might be a good time to decide if you want to play the gambit. Black is one passive move away from being squished. For example, Rad8 is punished severely by f5, as are most other moves. Black absolutely must try to prevent this actively with ..f5. Even then, after ef Black can also stumble with gf, after which once again f5 by White is just brutal. Here's a position Black could resign. 

Again, Black can improve. But the question is whether the second player will tread the right path. And all this assumes Black has put up a good fight to prevent the pawns from advancing. Here is what can happen if Black does not. 

Black's moves are all plausible, but White is stomping all over the Kingside and there is no way to stop it. 

The experiment

Update: The Halloween is Spreading

And now some bonus material. I've been playing Be4 in the ...Ng6, ..d5,..c6 main line, but after receiving ..f5 and getting clobbered by ruzomberok (who admittedly has reached 2700 and thus would smash me regardless) I decided to give the Bb3 line another look. Ruzomberok (Martin Lokander) is the author of The Open Game for Black and was better prepared for most. However, having demolished me he subsequently opened up Leela and we took a look at the main line. Leela thinks the position is playable for White. Here's an example line where White is doing fine. 

Here Black isn't succumbing by any means, but on the other hand, castling is impossible. Leela evaluates the position as -0.33, which is very high by Halloween standards! What's not to love? Martin has since succumbed to Halloween Gambit fever, and scored 3.5/4 in his first outings with it. Here's an example played on LiChess against a 2460 player. 

where Black resigned. His next opponent, even stronger at 2517, also declined the gambit and lost. Finally, a 2249 bot accepted and played the main line - but failed to define the advance f5 leaving White the more pleasant position. See the game was ultimately drawn, but Lord Barre (2412) was not so lucky in the main line. You can view that game but here it is for convenience. 

It seems that Black can so easily lose the fight for f5 and surrender too much time and space.

Update: (late Feb 2021)

Lately, I've been having a bit more success. One opponent played four straight games against me, each time admitting the Halloween Gambit and each time returning the piece. I won the first four games straight. And here's a recent game against a different, higher-rated opponent, just in case you think this gambit is reserved for <2000 players. 

Oops. I check the spreadsheet and it looks as if my performance rating with the Halloween is pretty good. In fact if I only got to play this opening and nothing else, I'd be North of 2300. Here's my hypothetical rating trajectory starting at 2100 and including only Halloween Gambit games. 

And here is the running tally of "extra games won" relative to my normal winning percentage. As you can see, I am scoring a huge +0.13 points per game, winning six more games than I otherwise would have. Doesn't that make you want to try it?