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Calculation in Chess · Yatish Chandra Shukla

The Blunder Check

Ten seconds before every move

In this lesson you will learn

Why even strong players blunder — and when
A ten-second routine to run before every move
The most common kinds of blunder, and how to catch them
How to use the blunder check without running out of time

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.

10.1 Why We Blunder

A blunder is a move that throws away material or the game in one stroke — usually to a simple tactic the player could easily have seen. Every chess player blunders sometimes, even world champions. But beginners blunder far more often, and almost always for the same few reasons:

Excitement. You have found a move you like, and you play it at once — without looking at your opponent's reply.

Relief. You have just escaped from danger, or just won material, and you relax.

Tunnel vision. You are so focused on your own attack that you forget your opponent has pieces too.

Time trouble. The clock is running low, and you skip every check.

Notice that none of these is about lack of knowledge. A blunder is almost never a move you could not have understood. It is a move you did not check. That is good news, because checking is a habit — and habits can be trained.

10.2 The Ten-Second Routine

You have chosen a move. Your hand is moving towards the piece. Stop. Before you touch it, run this routine:

1. Imagine the move is played. Picture the board with your piece on its new square — and the square it has left now empty.

2. Check, capture, threat — for your opponent. In that new position, what checks does your opponent have? What can they capture? What did your move leave undefended?

3. Look at the square you left. What was the piece doing there? Was it defending another piece, a square near your king, or the back rank?

4. Then, and only then, play the move.

The whole routine takes about ten seconds once you are used to it. It is the single most valuable habit in this book.

LessonYour move is not finished when you find it. It is finished when you have looked at it through your opponent's eyes — one last time.

10.3 Five Common Blunders

Most blunders belong to a small family. Learn to recognise them:

Blunder	What goes wrong
Leaving a piece loose	A piece without a defender can be won by any fork or double attack.
Moving a defender	The piece you moved was guarding something important, which now falls.
Ignoring a check	Your opponent has a check that forks, skewers or starts a mating attack.
The poisoned capture	You win material, but the capture opens a line or pulls your piece away from the defence
Forgetting the back rank	Your king has no escape square, and a rook or queen can reach your first rank.

TipUse the routine every move — not only in sharp positions. Most blunders happen in positions that look quiet and safe.

10.4 What About the Clock?

"Ten seconds every move? I will run out of time!" In a game of forty moves, ten seconds a move adds up to less than seven minutes. Most players lose far more time than that trying to save positions they have just thrown away. When you are short of time, shorten the routine to a single question: "What checks does my opponent have after my move?" That one question catches a large share of all blunders.

10.5 Worked Examples

Study each example as if it were a puzzle: cover the solution, calculate, and only then read on.

Diagram 10.1Black to move

Example 10.1

Black is about to play 1...c6. Run the blunder check before the move is made: is it safe?

Find the key move.

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.

Diagram 10.2White to move

Example 10.2

White is about to play 1.♗a7. Run the blunder check before the move is made: is it safe?

Find the key move.

LessonLook for squares from which one piece attacks two targets at the same time — especially with check.

Diagram 10.3White to move

Example 10.3

White is about to play 1.b3. Run the blunder check before the move is made: is it safe?

Find the key move.

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 10.4White to move

Example 10.4

White is about to play 1.h4. Run the blunder check before the move is made: is it safe?

Find the key move.

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 10.5Black to move

Example 10.5

Black is about to play 1...♗h3. Run the blunder check before the move is made: is it safe?

Find the key move.

LessonKeep a score card of every capture, and stop the count only when the captures run out.

Diagram 10.6White to move

Example 10.6

White is about to play 1.♗f6. Run the blunder check before the move is made: is it safe?

Find the key move.

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 10.7White to move

Example 10.7

White is about to play 1.♔f1. Run the blunder check before the move is made: is it safe?

Find the key move.

LessonLook for squares from which one piece attacks two targets at the same time — especially with check.

Diagram 10.8White to move

Example 10.8

White is about to play 1.♘d2. Run the blunder check before the move is made: is it safe?

Find the key move.

LessonLook for squares from which one piece attacks two targets at the same time — especially with check.

Diagram 10.9White to move

Example 10.9

White is about to play 1.♔b1. Run the blunder check before the move is made: is it safe?

Find the key move.

LessonLook for squares from which one piece attacks two targets at the same time — especially with check.

Diagram 10.10White to move

Example 10.10

White is about to play 1.♘d5. Run the blunder check before the move is made: is it safe?

Find the key move.

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

Blunders are rarely about knowledge — they are about moves that were not checked.
Before you touch a piece: imagine the move, scan your opponent's checks, captures and threats, and look at the square you are leaving.
Know the five common blunders: loose pieces, moved defenders, ignored checks, poisoned captures, the back rank.
Short of time? Ask just one question: "What checks does my opponent have after my move?"

Exercises · Lesson 10

In each puzzle a player is about to make a move. Run the blunder check: is the move safe? If not, find your opponent's strongest reply.

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Exercise 10.1Question

White to move

White wants to play 1.♔d4. Run the blunder check: is it safe?