RESISTENCIA DE MATERIALES

When you give two attacks at once, one move creates two attacks by two different pieces at the same time. Notice how this is different than the fork, where one piece attacks two pieces at the same time.

Patrick’s Pointers

When I was a kid, someone gave me a great piece of advice: “When you see a good move, don’t make it right away; sit on your hands and make sure there isn’t a better move.” Diagrams 54–56 show White benefiting from this advice.

Does that sound impossible? The idea is simple, really: One piece moves and attacks something, and once it is out of the way, another piece behind it is “discovered” to be attacking something else. Let’s take a look at two examples of this.

In Diagram 52, Black notices that the bishop would attack the queen if the knight were not in the way on c6. This gives Black an idea: Is there some useful square to move the knight to, so as to use the fact that the bishop will be attacking the queen?

In Diagram 53, we see the answer. Black plays 1 . . .Nb4!, an extremely strong move.

Because the bishop on b7 now attacks the queen, White must meet this threat. But the knight on b4 also attacks the rook. White cannot meet both threats at the same time and so must lose material.

Diagram 52: Black to move.

Diagram 53: Black plays 1 . . .Nb4! attacking the rook with the knight and the queen with the bishop.

Our second example shows that the discovered attack is such a strong tactic that there may be more than one good move. In that case, always look for the strongest possible discovered attack.

One possible discovered attack is to capture the pawn on a6 (see Diagram 54). The bishop can’t be captured (see Diagram 55), because of the threat to the queen. But this only wins a pawn; isn’t there a stronger move? Yes there is! White can play 1.Bg4!

(see Diagram 56) which attacks the rook on c8. Black must move the queen, and White will win the rook for the bishop.

Diagram 54: White to move.

Diagram 55: White plays 1.Bxa6. This wins a pawn, but White had a stronger move.

Diagram 56: White plays 1.Bg4! This wins the rook for the bishop.

Discovered Check

The most potent way to give two attacks at once is the discovered check. When you

give discovered check, you move one piece, and thereby uncover a check by another piece to the king. (The king suddenly “discovers” that it is in check!) I cannot

emphasize strongly enough how powerful this tactic is. Every grandmaster has deep respect for the discovered check—so much respect that if he can give discovered check he assumes that there must be something very powerful he can do, and if he sees that his opponent can give discovered check, he assumes there’s going to be trouble!

Diagrams 57 through 60 show how powerful discovered check can be. Diagrams 58 and 60 show a discovered check that wins the queen, because there is no way to remove the king from check and also prevent the queen from being captured. (In particular, notice in Diagram 60 that 1 . . .Qc7 can be answered by 2.Nxc7.)

Chess Talk

A discovered check is a special case of “two attacks at once,” where the attack that is “discovered” is a check to the king.

Diagram 57: Black to move.

Diagram 58: Black plays 1 . . .Bf3+!, which wins the queen.

Diagram 59: White to move.

Diagram 60: White plays 1.Ne6+!.

Chess Talk

A double check is when two pieces check the king at the same time.

Double check is only possible as a form of discovered check.

Double Check

Double check is an interesting twist on discovered check. The double check is a

discovered check, where the piece moving away decides to attack—the king! The king finds itself being checked by two pieces at once, and so there is no other way to meet the check than to move.

Basically, the double check is not a tactic to win material, but a tactic to attack the king. Still, since it’s a variant of the discovered check, I might as well introduce you to it in this chapter—and that gives me a chance to show you a beautiful execution of an attack against the king!

Diagrams 61 through 66 show an example of double check leading to checkmate. At the moment, in Diagram 61, Black has an extra knight. Probably he expected White to just win back the piece by using the pin on the e-file and playing 1.Re1. Instead, White plays a move that begins a forced sequence leading to checkmate!

In Diagram 62, White plays 1.Qd8+!!, catching Black off guard. What is White up to?

Well, it doesn’t matter—there is only one legal move anyway—so Black captures the queen with 1 . . .Kxd8 (see Diagram 63).

Diagram 61: White to move.

Diagram 62: White plays 1.Qd8+!!.

Diagram 63: Black plays 1 . . .Kxd8.

But now White’s clever plan is revealed: He plays 2.Bg5+!! (see Diagram 64), putting Black in double check. Because Black is in check from two pieces at once, he must move the king. The king has only two moves, to c7 or to e8. But no matter which way the king goes, White will give checkmate.

I urge you to figure out for yourself how White would give checkmate if Black moved the king to c7. (Here’s a hint: White gives checkmate with his bishop.) Black decides to play 2 . . .Ke8 (see Diagram 65). Now White has only one check, but it’s the check that ends the game: 3.Rd8# (see Diagram 66). What a finish!

Diagram 64: White plays 2.Bg5+!!.

Diagram 65: Black plays 2 . . .Ke8.

Diagram 66: White plays 3.Rd8#.

Exercise #1:White to move. How can White win a pawn by threatening a pawn fork between Black’s knight and bishop?

Exercise #2:White to move. Should Black be worried about 1.Nxh6+, or should White be worried because the knight is being attacked?

Exercise #3:White to move. What is White’s best move?

Exercise #4:White to move. Can White win Black’s queen? What is White’s best move?

Exercise #5:Black to move. Who should win this position?

Exercise #6:White to move. What is White’s best move?

Exercise #7:White to move. White plays 1.Bg5 in this position. What is his threat?

Can Black defend?

Exercise #8:White to move. White plays 1.Bg5 in this position. Does Black have the same problem as he had in Exercise #7?

Exercise #9:White to move (Wolff–Sagalchik, North Bay, 1996). I played 28.Nxe6, forking the queen and the rook on f4. What was my idea if Black played 28 . . .Rxe6?

Exercise #10:White to move. What is White’s best move?

Exercise #11:Black to move. What is Black’s best move? (Hint: The solution involves combining two different tactics.)

Exercise #12:White to move. This is a tough one! White thinks about playing 1.bxc8=Q+ Kxc8, giving both sides equal material and the position should be a draw. But White also sees the possibility to do better. How?

Exercise #13:White’s last move was 1.Qe2. What is his threat? Should Black play 1 . . .Ngf6 or not?

Exercise #14:Black played an amazing move in this position, 1 . . .Qg1+. What on earth was his idea after White captures the queen with his king?

Exercise #15:White to move (Volchok–Kreslavsky, USSR, 1970). It looks like Black will win back the bishop because of the pin against the rook. But White found a terrific way to turn the tables and win.

Exercise #16:White to move (Szabo–Bronstein, Zurich, 1953). Material is roughly even in this complicated position, but White found a way to cut through the

complications and get a winning material advantage. How? (Hint: 1.Qh8+ is not the right first move, but it is the right idea.)

Exercise #17:White to move. White wins if he finds the right way to give discovered check with the rook.

Exercise #18:White to move (Sznapik–Bernard, Poznan, 1971). White could capture Black’s f-pawns, but then Black defends with 1 . . .Ra7. Instead, White found a

beautiful way to win. How?

Exercise #19:Black to move (Kosalopov–Nezhmetdinov, Kazan, 1936). Black found an incredible way to win with 1 . . .Qxh2+!! 2.Kxh2. What should Black play now?

Exercise #20:White to move (Yermolinsky–Abroskin, Leningrad, 1972). How did White win Black’s queen?

Exercise #21:Black to move (Morozevich–Adams, Holland, 2001). How did Black force White to resign in one move?

The Least You Need to Know

The fork, the pin, the skewer, and “two attacks at once” are very effective tactics for winning material.

Discovered check is especially potent. Every grandmaster uses it when he can, and avoids falling victim to it whenever possible!

Double check is a version of discovered check. It is a very useful tactic for giving checkmate.

Practice recognizing these tactics with the exercises, and then use them to win material in your games.

Chapter 7