Exercise 3.1Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
3
Calculation in Chess · Yatish Chandra Shukla
Seeing Through Your Opponent’s Eyes
In this lesson you will learn
- How to read the message in your opponent's last move
- The four things every move can change on the board
- The "pass" trick for finding hidden threats
- How to choose a move that answers the threat and keeps your plans
Every board on this page is live. Move the pieces by tapping or dragging, click any move in the lines to see that position, and press ↺ to start again.
3.1 Every Move Is a Message
When your opponent makes a move, they are telling you something. Maybe they want to attack your king. Maybe they want to win a pawn. Maybe they are setting a trap. Beginners often ignore this message and simply carry on with their own plan — and then they are surprised when something on the board suddenly goes wrong.
The first of our three questions was: What does my opponent want? In this chapter we learn to answer it properly. It is the most important defensive skill in chess, and it is also a calculation skill: to find your opponent's threat you have to play their moves in your head.
NoteMany games between beginners are decided not by brilliant attacks, but by one player simply not noticing the other player's threat. Learning to see threats will win you more points than learning any opening.
3.2 Four Things a Move Can Change
When a piece moves, it changes the board in four ways. After each of your opponent's moves, ask about all four:
1. What does the piece attack from its new square? Look along every line the piece now controls. Does it hit one of your pieces? Does it hit a square next to your king?
2. What line did it open? When a piece moves away, the piece standing behind it may suddenly see further. A bishop, rook or queen can be "switched on" by a move of another piece.
3. What did it stop doing? On its old square the piece may have been defending something or blocking something. Now that job is no longer done — perhaps there is a target for you.
4. What can it do next move? Imagine your opponent could move again. Which check, capture or threat would they play?
The fourth question leads us to the most useful trick in this chapter.
3.3 The "Pass" Trick
Here is a simple way to find any threat. Imagine that it is your opponent's turn again — as if you had passed and made no move at all. Now run the CCT scan from their side: which checks, captures and threats would they have?
Whatever their best move would be in that imaginary position, that is their threat. If it wins material or gives mate, you must do something about it with your real move.
LessonBefore you choose your move, imagine you pass. Ask: "If my opponent could move twice in a row, what would they play?" That move is the threat you have to stop.
Once you know the threat, there are usually several ways to deal with it:
Move the attacked piece to a safe square.
Defend it with another piece, so that taking it would cost your opponent material.
Block the line of attack by putting a piece in between. Capture the attacking piece, if you can do it safely.
Counter-attack with a bigger threat of your own — but only if you have calculated that your threat really is bigger.
Do not grab the first defence you see. Look at all of them, and choose the one that also helps your own position.
3.4 Example: A Threat Hidden in Plain Sight
Diagram 3.1White to move
Example 3.1
White to move. White would like to attack with g5, driving away the knight on f6. Use the "pass" trick first.
Imagine White passes. What would Black play? Run Black's CCT scan, starting with checks. Black has one: 1...♘xc2+ — and look at White's king. Every square around it is blocked by White's own pieces: the knight on d1, the bishops on d2 and f1, and the pawns on e2 and f2. So 1...♘xc2 would not just win the queen — it would be checkmate.
Now we know what Black wants, we can judge White's moves:
1.g5?? ignores the threat: 1...♘xc2#.
1.♕a4? saves the queen, but leaves c2 unguarded. Black answers 1...♕d7!, offering a queen trade: after 2.♘c3 ♕xa4 3.♘xa4 ♘c2+ the knight forks king and rook, and Black wins material.
1.♕c1! is the right answer. The queen leaves the knight's reach but still guards c2, so a knight check there can simply be captured.
LessonA king surrounded by its own pieces is in danger from knight checks, because a knight check cannot be blocked. Always ask which squares an enemy knight could check from.
3.5 Example: "But It's Defended!"
Diagram 3.2White to move
Example 3.2
White to move. Black's rook on b3 attacks the queen on d3. The queen is defended by the rook on d1. Is White safe?
Many players would stop thinking here: "The queen is defended, so taking it costs Black a rook. Fine." But use the pass trick and calculate one move further. If White passes:
1...♖xd3 2.♖xd3 ♕b1+! 3.♔g2 ♕xd3
White's rook on d1 had two jobs: guarding the queen and guarding the back rank. When it recaptures on d3, the back rank is left open, and Black's queen checks on b1 and then picks up the rook. Black wins a whole rook. The defender was overloaded.
So White must move the queen. 1.♕e4! is best: the queen escapes, keeps an eye on d5, and the position stays balanced. A careless move such as 1.dxe6?? would lose at once to exactly the sequence above.
Lesson"It's defended" is not the end of the calculation. Ask: after the recapture, what is my defender no longer doing?
3.6 Punishing the Last Move
Study each example as if it were a puzzle: cover the solution, calculate, and only then read on.
Diagram 3.3White to move
Example 3.3
Black has just played 1...♔xg8? What did this move overlook?
Find the key move.
Solution. 1.c8=♕+ ♔f7 2.♕c7+ ♔e8 3.♕g7 The pawn promotes to a queen.
Black's other defences do not help:
1.c8=♕+ ♔g7 2.♕c7+ ♔f6 — White is clearly better.
1.c8=♕+ ♔h7 2.♕d7+ ♔h6 — White is clearly better.
Compare a natural alternative, 1.♔c3?: after 1.♔c3 g1=♕ 2.c8=♕+ the position is about equal. That is far less than the key move achieves.
LessonLook for squares from which one piece attacks two targets at the same time — especially with check.
Diagram 3.4White to move
Example 3.4
Black has just played 1...♕xd5? What did this move overlook?
Find the key move.
Solution. 1.♕xg7 ♔b8 2.♖c1 a6 3.h5 — the rook on g7 was not defended. White wins a rook.
Black's other defences do not help:
1.♕xg7 a6 2.♖c1+ ♔b8 — White is winning.
1.♕xg7 ♕c6 2.h5 ♔b8 — White is winning.
Compare a natural alternative, 1.♖c1+?: after 1.♖c1+ ♖c7 2.♖xc7+ Black is a little better. That is far less than the key move achieves.
LessonA piece without a defender is the easiest target on the board. Before every move, ask which pieces are loose — yours and your opponent's.
Diagram 3.5White to move
Example 3.5
Black has just played 1...a6? What did this move overlook?
Find the key move.
Solution. 1.cxd6+ ♖xd6 2.♘b4 ♖c8 3.♖c1 White wins the queen for a pawn.
Black's other defences do not help:
1.cxd6+ ♔f8 2.♘b4 ♔g7 — White is winning.
1.cxd6+ ♔e8 2.♖xa6 ♔f8 — White is winning.
Compare a natural alternative, 1.♘b4?: after 1.♘b4 ♕f4 2.♘xc6+ Black is clearly better. That is far less than the key move achieves.
LessonChecks come first in the CCT scan because they leave the opponent the fewest replies.
Diagram 3.6White to move
Example 3.6
Black has just played 1...a5? What did this move overlook?
Find the key move.
Solution. 1.fxg3 bxc4 2.♘xc4 — the queen on g3 was not defended. White wins the queen.
Black's other defences do not help:
1.fxg3 axb4 2.♘xb5 ♘b3 — White is clearly better.
1.fxg3 exd3 2.♗xd3 axb4 — White is clearly better.
Compare a natural alternative, 1.♘xb5?: after 1.♘xb5 ♕e5 2.♗b2 Black is clearly better. That is far less than the key move achieves.
LessonA piece without a defender is the easiest target on the board. Before every move, ask which pieces are loose — yours and your opponent's.
Diagram 3.7Black to move
Example 3.7
White has just played 1.b3? What did this move overlook?
Find the key move.
Solution. 1...♕e5+ 2.♗e2 ♕xa1 3.♘a3 ♘f6 — the queen attacks the king and the rook at the same time. Black wins a rook.
White's other defences do not help:
1...♕e5+ 2.♘e2 ♕xa1 3.♘ec3 — Black is winning.
1...♕e5+ 2.♕e2 ♕xa1 3.♔d1 — Black is winning.
Compare a natural alternative, 1...♗f5?: after 1...♗f5 2.♘c3 ♕d7 the position is about equal. That is far less than the key move achieves.
LessonLook for squares from which one piece attacks two targets at the same time — especially with check.
Diagram 3.8Black to move
Example 3.8
White has just played 1.♔h1? What did this move overlook?
Find the key move.
Solution. 1...♕xe2 2.♕g3 ♕xc4 3.♖be1 ♖hf8 Black wins a bishop and a pawn. White's other defences do not help:
1...♕xe2 2.♕xe2 ♖xe2 3.c5 — Black is clearly better.
1...♕xe2 2.♕h4 ♖hf8 3.♖xf8 — Black is clearly better.
Compare a natural alternative, 1...♗a6?: after 1...♗a6 2.♖f2 ♘f7 Black is a little better. That is far less than the key move achieves.
LessonMaterial can be given away when the result has been calculated to the end. Count at the end of the line, not after the first move.
Remember
- Every move your opponent plays carries a message. Read it before you think about your own plans.
- Ask four questions: What does the piece attack? What line did it open? What did it stop doing? What can it do next?
- Use the "pass" trick: imagine your opponent could move twice. Their best move is their threat.
- To meet a threat you can move, defend, block, capture or counter-attack. Compare them before choosing.
- A counter-attack is only good if you have calculated that your threat is bigger than theirs.
Daily PracticeIn your next games, say your opponent's threat out loud (or in your head) after every move they make: "He wants to play ...Nxe4." If you cannot name a threat, say "No threat" — but only after running the scan.
Exercises · Lesson 3
In most of these puzzles your first job is to find what your opponent is threatening. Use the "pass" trick, then choose the best way to meet the threat — or to punish your opponent if they made a mistake.
Exercise 3.2Find the move
Black to move
Black to move. What is White threatening, and how should Black meet the threat?
Exercise 3.3Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
Exercise 3.4Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
Exercise 3.5Find the move
Black to move
Black to move. What is White threatening, and how should Black meet the threat?
Exercise 3.6Find the move
Black to move
Black to move. What is White threatening, and how should Black meet the threat?
Exercise 3.7Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
Exercise 3.8Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
Exercise 3.9Find the move
White to move
White to move. What is Black threatening, and how should White meet the threat?
Exercise 3.10Find the move
Black to move
Black to move. What is White threatening, and how should Black meet the threat?
Exercise 3.11Find the move
Black to move
White has just played 1.♗h4? What did this move overlook? Punish it.
Exercise 3.12Find the move
White to move
Black has just played 1...♗c3? What did this move overlook? Punish it.
Exercise 3.13Find the move
Black to move
White has just played 1.♖c4? What did this move overlook? Punish it.
Exercise 3.14Find the move
Black to move
White has just played 1.♖h3? What did this move overlook? Punish it.
Exercise 3.15Find the move
Black to move
White has just played 1.♔d2? What did this move overlook? Punish it.
Exercise 3.16Find the move
Black to move
White has just played 1.♔h2? What did this move overlook? Punish it.
Exercise 3.17Find the move
White to move
Black has just played 1...♕g5? What did this move overlook? Punish it.
Exercise 3.18Find the move
Black to move
White has just played 1.♖c1? What did this move overlook? Punish it.
Exercise 3.19Find the move
White to move
Black has just played 1...♕a6? What did this move overlook? Punish it.
Exercise 3.20Find the move
White to move
Black has just played 1...♔g8? What did this move overlook? Punish it.
Exercise 3.21Find the move
Black to move
White has just played 1.♕c1? What did this move overlook? Punish it.
Exercise 3.22Find the move
Black to move
White has just played 1.♘b1? What did this move overlook? Punish it.
Exercise 3.23Find the move
Black to move
White has just played 1.b3? What did this move overlook? Punish it.
Exercise 3.24Find the move
White to move
Black has just played 1...cxd5? What did this move overlook? Punish it.
Exercise 3.25Find the move
White to move
Black has just played 1...♕e7? What did this move overlook? Punish it.
Exercise 3.26Find the move
White to move
Black has just played 1...h5? What did this move overlook? Punish it.
Exercise 3.27Find the move
Black to move
White has just played 1.♖a2? What did this move overlook? Punish it.
Exercise 3.28Find the move
Black to move
White has just played 1.♕b3? What did this move overlook? Punish it.
Exercise 3.29Find the move
Black to move
White has just played 1.♘h3? What did this move overlook? Punish it.
Exercise 3.30Find the move
White to move
Black has just played 1...b5? What did this move overlook? Punish it.