The topic of momentum is one of the hardest to understand in chess. Some world-class players, even challengers to the World Championship, have had a less than sufficient grasp of this concept.
In short, momentum is the need to proceed with a dynamic enterprise - aka an attack - with as much energy and urgency as possible.
At times, this means a total disregard for material and at others, less so. Getting a strong feeling for momentum is the key skill to acquire when studying attacking chess.
Somehow it came very natural to me, but I have witnessed many others struggle acquiring this skill to such an extent that I have come to regard it as the most difficult skill to acquire in chess.
In Dvoretsky's model of four archetypes of players, the activist is the type blessed with a strong intuition for the attack. There is a lineage with Anderssen, Morphy, Tartakower, Tal, ending with Shirov and of course Anand.
Working on acquiring a strong sense of dynamics starts with recognising what it is and not mistaking it simply for calculation. While calculation is even more important and challenging in attacking chess than in most other parts of chess, it is still governed/assisted by an underlying sense of what to calculate, based on our belief of the needs of the position.
In the following game from the 2020 Spanish Championship, we shall see the concept of momentum in action.
Moreno Ibanez M. (2283) - Ruiz Buenida M. (2044) 2020
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bc4 e6 7.Be3 Be7 8.Bb3
8...0-0? After looking at this game and studying the theory for a bit, I have come to the conclusion that this is a positional mistake. The reasoning is simple: White cannot throw an attack up the board before he has a clear target. This only appears the moment Black has castled.
8...a6 9.Qe2 Qc7 10.0-0-0 Na5 is the critical line. But I shall not leave you with that. Here is a little novelty that may confuse some: 11.Ba4+!?N
(11... b5? is an obvious blunder: 12.Ncxb5!)
(11... Bd7 is the most natural move, but after 12.Bxd7+ Nxd7 13.f4 0-0 14.f5, White has decent chances. For example: Qc4 15.Qg4 Nf6 16.Qg3 with a slight edge.)
12.Kb1 b5 13.Bb3 Rb8 14.Rhe1 h6 with a very novel playing ground.
9.Qe2 a6 10.O-O-O Qc7
I find 10...Nxd4 11.Bxd4 b5 entirely unattractive. White plays for open piece play: 12.e5 dxe5 13.Bxe5 Qb6 14.Ne4
Nxe4 (14...Nd7 15.Bd6 with a lasting positional advantage.) 15.Qxe4 Bg5+ 16.f4 Bb7 17.Qe2 Bh6
18.Rd6N (18.Kb1 Rfd8= with equal chances was Panbukchian – Ermenkov, Bulgaria 1988.) 18...Qc5 19.Kb1! a5 20.a3. Black is under some pressure and not able to easily generate counterplay. A typical line would be: a4 21.Ba2 b4 22.axb4 Qxb4 23.Rd4 Qa5 24.Rhd1 Rad8 25.g3
with strong domination. White's king would be weak if he was not so well placed.
Let’s go back to the game.
11.Rhg1 b5 12.g4 b4
I also do not like the Black position after: 12...Na5 13.g5 Nxb3+ 14.axb3 Nd7 15.f4! provides White with a strong attacking position.
Here are some examples. 16...Bb7 is untested as of now and probably best. But White still has better chances after 16.f5!
If 15...Nc5 16.b4 Na4 17.Nxa4 bxa4 18.f5
d5 (18...e5 19.f6 exd4 20.fxe7 Qxe7 21.Rxd4 White has a big advantage)
19.g6!N fxg6 20.fxg6 Bf6 21.exd5+/-)
If 15... b4 16.Nf5!!
Now If 16...exf5 17.Nd5 Qd8 18.exf5 Re8 19 Bd4 Bf8 20.Qh5 Bb7
21.Nf6! Nxf6 22.gxf6 Re4 23.Rd3 Qa5 24.fxg7 Rxd4 25.Qxh7!! 1-0 Dijkhuis – Van Wely, Netherlands 2017.)
And if 16...Bd8
17.Nd5!! exd5 18.Qh5 Ne5
(19.fxe5 dxe5 20.Rxd5 was successful in Sanchez Aller – Pena Gomez, Ourense 2007. But after Bxf5 21.exf5 a5 the game is still very much on.) 19...Kxg7 20.Qh6+ Kg8 21.f5! White wins.
Let's go back to the game.
13.Nxc6! Qxc6 14.Nd5!
This powerful move sets the scene for the middlegame. White plays with great urgency. At least for a while. Leaving his opponent unable to get his pieces out in time.
14.exd5? Technically, this is already a losing mistake.
Better would be 14...Nxd5! 15.exd5 Qc7 with an advantage to White, but still with a chance to weather the storm with decent defence, was the way to go.
15...dxe4?! This only helps White.
15...Nxe4 16.Bxd5 Qa4 would seek to make some complications. And, importantly, keep the g-file closed. 17.Bxe4
(17.Bxa8?! Nc3 18.bxc3 Be6 is better for White, but still terribly complicated. Nordstrom – Wikstroem, Sweden 1975.)
17...Be6 18.Bd4 (18.Rd4? would spell a total loss of momentum. Rac8 and Black was already fully back in the game in Ivanchuk – Grischuk, Odessa 2007.) 18...g6
(18...Qxa2? loses on the spot: 19.Qh5 g6 20.Qh6 f6 21.gxf6 Bxf6 22.Rxg6+ with mate on the horizon.)
This position is very instructive and my students as well as real life humans, have struggled with it.
19.b3!! A very imaginative move. White does not want to part with the strong bishops before it is entirely necessary.
(19.Bxa8?! Rxa8 20.a3 bxa3 21.b3 gives Black a pawn on a3 and White the advantage. For the technically inclined player, this may look attractive, until he starts contemplating the advance of the second a-pawn and his lack of king security. Still, the extra material makes White the favourite here, but with a lot of difficult decisions ahead.
19.Bd5? has been a popular suggestion among my younger students.
Eying the dark squares around the black king, they seek to checkmate on them.
Bxd5 20.Qxe7 But here they are faced with the reality of momentum. It is Black to play and White never gets time to enjoy his mating ideas. Rac8 21.Rd2 Qxa2 22.b3 Rc3! It is White who will be mated after 23.Re2 Qa1+ 24.Kd2 Rxc2+! and so on.
19.h4?! Rac8 20.h5 Qxa2 21.f4! Rc4! gave Black unnecessary counterplay in Vedder – Abasov, Bilbao 2014, a game Black eventually won.)
19...Qxa2 Retreat is not an option. 20.Kd2! Qa5 21.Ra1 Qd8 (White is also dominating after 21...Qc7 22.Bxa8 Rxa8 23.Rxa6 Rc8 24.Ra2.)
(White suffered a swift collapse in the following game: 22.Bxa8?! Qxa8 23.Ra5? Bd8 24.Rxa6 Qd5 25.Qe3 Bc8 26.Ra4 Bd7 27.Rxb4? Ba5 28.c3 Bxb4 29.cxb4 Re8 0-1 Kopp – Dambrauskas, corr. 1986.)
22...Rc8 (22...a5 23.Qe3! White is a pawn down, but at the same time entirely winning. h4-h5 is coming and Black is too passive to create real counter-chances (although he should try). On top of this White has the idea of Bb2 and Qd4 in some scenarios.) 23.Rxa6 Black is dominated and will have to wait and see if his opponent is able to convert the advantage or not.
Let’s go back to the game when Black played 15...de4
16.gxf6 Bxf6 17.Bd5 Qa4
White has a winning attack already. The great lead in development cannot be contained if it is wielded with great force.
18.Qh5!? A strong and natural move, bringing the queen to the attack. Here are some moves lacking momentum.
18.Bd4 Bxd4 19.Rxd4 would be met with Be6 20.Bxa8 Qxa2 with counter-chances.
18.Bxa8? Qxa2 19.Kd2 Bf5 20.Bb7 would be good for White. But Black would play 18...Be6! using momentum to create his own counter-chances.
18.Qc4? Be6! and Black is already not worse.
White could also have sought to exchange Black's best piece with 18.Bg5!
Strategically this is less principled, but practically, it removes all counterplay and thus leaves Black with no real chances to mess things up.
When you have an advantage, sometimes removing counterplay is all that is needed.
18...Be5 (18...Bxg5+ 19.Rxg5 would be bad. Black will either get killed on the kingside or have to give up the exchange. This time without counterplay, as the bishop is no more.) 19.Qxe4 Be6 There is nothing else. (if 19...Rb8 20.f4 and White wins and if 19...Re8 20. Bxa8 Bxb2+ 21.Kxb2 Rxe4 22.Bxe4 b3 23.cxb3 Qe8 (23...Qxe4 24.Rge1!) 24.Bf6 1-0 Ristoja Lehtimaeki – Peljo, Finland 1972.)
(20.Bxe6 fxe6 21.f4 Rac8
22.Kb1! and White wins. (22.fxe5?! d5 is still an advantage, but entirely unnecessary.))
20...Bxd5 21.Qxd5 b3 22.axb3 Qa1+ 23.Kd2 Qxb2 24.fxe5+- and White later won in Viel – Navrotescu, Agneaux 2018.
Back to the game after 18.Qh5!?
18... Be6 Black has to bring the pieces out. There can be no delay.
The same goes for White.
19.Bxa8?? would be entirely wrong. After Bxb2+ Black wins in an almost mirrored way.
19...Kxg7 20.Qh6+ with mate
20.Rg1 Rfc8 There is nothing else. The second sacrifice on g7 is going to hurt.
If 20... Rac8 21.Rxg7+ Kxg7 22.Qg5+ Kh8 23.Bd4+ f6 24.Bxf6+ Rxf6 25.Qxf6+ Kg8 26.Bxe6# 1-0 Sinacori – Scholz, ICCF corr. 1990.
This is the most instructive moment of the game and one that had been reached in a few games in the past.
21.Bxe4? A loss of momentum.
21.Rxg7+! is the principled move that gives a winning attack. Kxg7 (21...Kf8 22.Rxf7+!) 22.Qh6+ Kg8 23.Bxe4
White has a winning attack. The double rook sacrifice has eliminated Black's defence on the kingside entirely. b3
(Otherwise if 23...Rxc2+ 24.Bxc2 Rc8 25.Qxh7+ Kf8 26.Qh8+ Ke7 27.Qxc8 1-0 Jantunen – Peraelae, Finland 1971.
And if 23...f6 24.Bxh7+ 1-0 Tichy – Hejna, Czech Republic 1995.)
24.Bxh7+ Kh8 25.Bf5+ Kg8 26.Qh7+ Kf8 27.Bh6+
27...Ke7 (27...Ke8 28.Qg8+ is very similar.) 28.Bg5+ Ke8 29.Qg8+ Kd7 30.Qxf7+ Kc6 31.Bxe6
White's attack is entirely winning. Kb6
(31...Qe4 32.Qd7+ Kb6 33.Be3+ Ka5 34.Bxb3 and White is winning.)
(32...Rc5 33.Bd5! Rb8 34.Qe7 and White wins.)
33.Bxc8 Rxc8 34.Qf5+ Rc5 35.Bxc5 and White wins.
After 21.Be4? Black played 21...f5?
Black was given a golden opportunity, but either did not have the required imagination or the feeling for momentum to see that his opponent had missed the moment.
21...b3! would be very strong
(22.Qh6 and 22.Qxh7+ are both met with 22...Kf8-e7/e8 and the attack is stalling.)
22...Kf8!! (Black could also start with 21...Kf8, as the computer points out, but no one would ever play like that).
(After 23. Qxh7 Black has a fantastic multipurpose move - Qa5!!
Black is creating threats against the white king while at the same time defending his own.
(23...bxa2 would lead to mate quickly 24.Qg8+ Ke7 25.Bg5+ Kd7 26.Rxf7+ Bxf7 27.Qxf7#)
24.Bd2 trying to gain a tempo, but Black continues in the same path.
(The key defensive property of Black's last move comes out after 24.Qg8+ Ke7 25.Bg5+ Qxg5+! and Black wins.
And after 24.Kd1 bxc2+ 25.Bxc2 Qd5+ 26.Bd3 Qxa2 the queen is defending the f7-square, while preparing death and destruction in the other end.)
25.Bh6 (25.Bd3 bxa2!) 25...Qf1+ 26.Kd2 Qxf2+ 27.Kd1 Ke7 Black is completely winning. For example: 28.axb3 Rh8!)
And after 23.Qh6 Ke8 24.Qxh7 Is very similar.
24...Qa5!! Once again this is the key move giving Black the upper hand.
(24...d5?! looks tempting, but White has an inglorious dynamic escape.
25.Rxf7!! Bxf7 26.Bf5!! Rxc2+
(26...bxa2? would lose to 27.Qh8+ Ke7 28.Qe5+ with mate approaching.)
27.Kd1 Qc6 28.Qh8+ Ke7 29.Qh4+ Kf8 30.Qh8+ Bg8!? 31.Bh6+ Ke7 32.Qg7+ Bf7 33.axb3 Rxf2 34.Bg5+ Kd6 35.Qf6+ Kc7 36.Qxf7+ Kb8 37.Qf8+ Kb7 38.Qf7+ with a draw.)
25.Kd1 d5 26.Rxf7 (26.Bf5 bxa2 and the king will dance away.) 26...Bxf7 27.Bf5 bxc2+ 28.Ke2 Qb5+! 29.Kf3 Qxb2 and Black wins.
After 21...f5? 22.Qh6! was played in the game.
22.Rxg7+? Kxg7 23.Bd4+ Kf8 only gives White enough attack to provide him with a perpetual check.
And after 22.Bd4?? fxe4 23.Rxg7+ Kf8 the black king is strangely safe.
23.Bxa8? This is grand sloppiness. Black is by no means forced to recapture.
23.Bd4! would have cut the game short.
White was no doubt counting on 23...Rxa8? 24.Bd4 and his opponent's resignation.
24.Rxg7 Qxg7 25.Qxe6 Rxa8 26.Qd5 Re8 27.Bd4 Re5
A horrible squandering of the advantage. White was still winning, although it required more skill than before.
28.Bxe5! It is important to take on e5 directly and not include 28.Qa8+ Qg8 in the equation, as it would draw out the black king.
Now Black has two options: 28...Qe5 and 28...de5
28...Qxe5 loses 29.Qxe5+ dxe5 White wins the pawn ending because the black king is stuck in the far corner. Had it been on g8, Black would have been fine.
The following breakthrough is the key point. Black can try various things to delay the inevitable and confuse his opponent, but the clarity of this variation is the reason why White is winning:
30.c3! bxc3 31.b4! Kg7 32.a4 Kf7 33.b5! axb5 34.a5 and the pawn queens.
So Black should take with the pawn - 28...de5.
But anyway after 29.Qd8+ Qg8 30.Qf6+ Qg7 31.Qxf5 gives White a winning queen ending, on the account of Qg1+ 32.Kd2 Qxh2 33.Qf8#
After 28.Qd6 followed 28...Qg1!
This is momentum in its most basic form. The side to move wins.
29...Qe1+ 30.Kd3 Qe2#
Momentum and inclusion of all the pieces are the core skills that all attacking players need to develop a good feeling for.