Lesson 9 - Basic Chess Tactics: The Discovered Attack

"Discovered check is the dive bomber of the chess board."
- Rueben Fine
"Even the laziest king flees wildly in the face of double check."
- Aaron Nimzowitsch

The discovered attack can occur when a long range piece (queen, bishop or rook) has its way blocked by one of its friendly piece. The blocking piece is preventing the long range piece to deliver a direct attack to the enemy, which could be on a piece or for a checkmate threat. By removing the blocking piece, the power of the long range piece is then revealed and the opponent needs to deal with this attack. See the diagram below for an example of this tactic.

It is White's turn to play and the b3 bishop could check the black king if the c4 pawn was not blocking its way... well, White only needs to push the pawn by playing 1. c5 to make the check happen!

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Discovered Check given by the b3 bishop

Diagram 9.1 - Discovered Check
given by the b3 bishop

This example demonstrates what is a discovered attack but we could not appreciate all the potential this tactic is hiding! In the next example, Black is using the discovered attack against the white queen to win a pawn (a very modest prize...).

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Discovered attack winning a pawn

Diagram 9.2 - Discovered attack
winning a pawn

As we can see in the example above, when the d file is opened (meaning that there is no pawn on it), queenside castling often offers the possibility to do discovered attacks on the enemy queen still occupying its starting square because the rook occupies the same file as the queen after long castling. Stay vigilant about this possibility... that could help or save you one day!

Are you starting to feel the potential of this tactic? That's not all... the true power of the discovered attack occurs when we attack two pieces at the same time: the double attack. In the following diagram, White has the possibility to get a big material advantage. Black believes that his position is solid seeing that the center is blocked for white pieces. However, White has a move allowing him to open the lines in the center... analyse the position and try to find the discovered attack that is winning for White:

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The potential of a discovered attack

Diagram 9.3 - The potential of
a discovered attack

White should play 1. d6! and do a discovered check on the black king with his bishop on c4. Moreover, by advancing, the pawn threatens the black queen. Since Black must take care of the check in priority, he cannot defend his queen. The best defense is then to block the check with the queen on e6 so at least he will get the bishop after it takes the queen.

As we can note with the previous example, the discovered attack is more effective when it involves the enemy king. Indeed, if the opponent is on check during the manoeuver, he has to put his king to safety before doing anything else. I have to warn you however that double attacks are not efficient all the times. In some cases, the opponent can save the day by using in-between moves (usually a check) and save both of the attacked pieces. See by yourself in the following example:

Diagram 9.4 - In-between defensive
move saving both attacked pieces

In the next section, we will learn that it is possible to do double attacks with another tactic: the fork. However, the discovered attack has a particularity that the fork does not have: it allows the possibility to do a double attack on the same piece. To complete the theoritical aspect of this tactic in beauty, let's study the impact of a double attack against the enemy king. For those of you that worked on the previous lesson on checkmating patterns, you will note that I am using the Philidor's Legacy study to demonstrate this particularity.

 

As we see in this last example, a double attack on the king forces the king to move to get out of check. That's something that is worth remembering...

Let's continue our journey in the tactical world with the next page on the forkonline chess tutorial.