Puzzle and study of positional sacrifices! - Chess Forums

Armalando06

Jun 4, 2023

0

#1

Hello everyone. You know I usually post interesting puzzles from my games on this forum; now, I'm going to do something different: I'll give you a puzzle which can hopefully help you to understand the fascinating concept of positional sacrifice, giving you some advice in the process. I hope higher rated players will approve what I say

Now, here's the starting position. We are in a Scandinavian defense, playing as white. First of all, you have to understand what's going on on the board: white has castled and has developed three out of four minor pieces, being ahead in development; black, on the other hand, has a better pawn structure (the d4 pawn is temporarily weak, due to the fact the c-pawn is blocked by two pieces) and chances to strike back in the centre and gain permanent control. Black has just played the mistake b5, trying to win a tempo on the bishop. Can you see how white can respond?

Nxb5!! is a beautiful positional sacrifice out of the opening. First of all, you have to ask yourself: why am I doing this? Of course you don't sacrifice a piece for nothing, there must always be some compensation: in this case, what is white gaining? Material-wise, you gain two pawns, which is pretty good (and your c-pawn is now a passed pawn); you win a tempo, because once you recapture with the bishop, it's check. That's it? Let's go forward.

Before analyzing this situation, you have to ask yourself: what if he plays something else? In the first place, if black refuted the sacrifice (which would have been correct) you're just up a pawn. You lose a tempo, but you have a lead in development and you created two weak isolated pawns, while the opponent's chances to strike in the centre do not exist anymore. What if, instead of blocking with the knight, he played Ke7? You don't really need to calculate, black can't castle anymore while the king is in the centre; with your lead in development, you can just destroy the opponent by keeping developing towards the centre (c4 to gain space, Re1, aiming at the king on x-rays, and, on a possible Nd5, his position will crumble in pieces). Now, back to our example, Nd7 played. This is still about the king in the centre: the knight has pinned itself, and a timely Nd5! puts more pressure on the pinned piece (pp on the pp, as Levy uses to say). Nf6 is the best attempt for black, but Bg5! pins the knight, so the knight on d7 is actually still hanging. Let's go ahead.

Now, you see what you need to do when you sacrifice. If there's no clear way to win, you constantly need to understand the strenghts and the weaknesses of your and your opponent's positions: there's compensation if you either create a dangerous weakness for him or a huge strenght for you (for example, in another game I sacrificed a kinght for three pawns, creating three connected passed pawns on the queen side: this is a potential winning factor, since not even a rook can compete against them in an endgame). At the same time, you have to anticipate every move, to understand if the weakness you've created can be attacked successfully. Now, after Qa5, attacking the bishop, you ask yourself: I'm putting a lot of pressure on the knight, but I still can't capture it, can I be patient and defend myself? The answer is: yes! You are miles ahead in developing, and you realize that the knight can't actually be defended anymore. c4 is a crucial move, because it covers the a4 square with the queen, allowing the bishop to retreat after a6 (actually, I played Qa4 in the game, using the pin on the rook, but that loses a big part of the advantage). In fact, after retreating, every rook move to defend the kinght allows a fork, so you are gaining back the material and winning a few pawns! Actually, Stockfish doesn't even want you to gain back the material, because you're dominating: it prefers you to either push the c-pawn or play Re1, attacking on x-rays the king, but that's just computer stuff.
So, what do you need to do after a sacrifice with no clear continuation? You need to calculate as much as you can and evaluate the final position you get, looking at the strenghts and weaknesses you created and at how to attack them. In general, if you win two pawns for a minor piece, big activity and space, the sacrifice should be playable, but don't think this is the only possible compensation! It can also come with open files/diagonals on the king, passed pawns, isolated pawns in the opponent's structure... I hope this small lesson will be useful for you!

Armalando06

Jun 4, 2023

0

#2

I think you’ll have some problems to visualize this on your phone

Arisktotle

Jun 5, 2023

0

#3

Good game play!