Project approval after AI review on November 2, 2026. Human proofreading is still pending.
Lesson 15
Exchange for a reason
- What you will learn
- You recognize which exchange helps you: one that removes an important defender.
- What you should already know
- What it means to gain time
- What checkmate is
- Lesson 3: Check, checkmate and stalemate
- Lesson 9: A move can gain time
Time: about 5 minutes
Thinking questions in this lesson
You can ask yourself these thinking questions in any position. They help you find a good move.
- What is the threat?
Step 1 of 6
Look first
Black has just played h7–h6, attacking your bishop on g5.
Your queen on d3 and bishop on c2 aim at h7. But a black piece is keeping watch.
Tap the black piece that prevents your queen from giving checkmate on h7.
Arrow keys move the focus across the squares. Enter or Space marks a square or removes the mark.
Choose a square from a list
Position as a list
White
- King g1
- Queen d3
- Rook e1
- Bishop c2
- Bishop g5
- Knight e2
- Pawn b2
- Pawn c3
- Pawn d4
- Pawn f2
- Pawn g2
- Pawn h2
Black
- King g8
- Queen d8
- Rook f8
- Bishop e7
- Knight b3
- Knight f6
- Pawn a4
- Pawn d5
- Pawn e6
- Pawn f7
- Pawn g7
- Pawn h6
Step 2 of 6
Decide
You can capture on f6 or b3, or retreat the bishop on g5. What helps you most?
The pawn on h6 attacks your bishop on g5. Which plan do you choose?
Arrow keys move the focus across the squares. Enter or Space selects a piece and moves it to a highlighted square. Escape cancels the selection.
Position as a list
White
- King g1
- Queen d3
- Rook e1
- Bishop c2
- Bishop g5
- Knight e2
- Pawn b2
- Pawn c3
- Pawn d4
- Pawn f2
- Pawn g2
- Pawn h2
Black
- King g8
- Queen d8
- Rook f8
- Bishop e7
- Knight b3
- Knight f6
- Pawn a4
- Pawn d5
- Pawn e6
- Pawn f7
- Pawn g7
- Pawn h6
Step 3 of 6
Try it
Your bishop on g5 is attacked. Capture the right piece with a bishop.
Arrow keys move the focus across the squares. Enter or Space selects a piece and moves it to a highlighted square. Escape cancels the selection.
Choose a move from a list
Position as a list
White
- King g1
- Queen d3
- Rook e1
- Bishop c2
- Bishop g5
- Knight e2
- Pawn b2
- Pawn c3
- Pawn d4
- Pawn f2
- Pawn g2
- Pawn h2
Black
- King g8
- Queen d8
- Rook f8
- Bishop e7
- Knight b3
- Knight f6
- Pawn a4
- Pawn d5
- Pawn e6
- Pawn f7
- Pawn g7
- Pawn h6
Step 4 of 6
Why does it work?
The knight on f6 defends h7. You offer an exchange: bishop for knight. But Black must not accept it, or your queen gives checkmate.
The exchange on b3 does not help your attack. Your bishop on c2 leaves the diagonal towards h7, and your bishop on g5 remains attacked: Black captures it with hxg5.
A retreat costs time. With the exchange on f6, you lose none.
Key idea
Exchange when doing so removes an important defender. If your piece is attacked, an exchange can be better than a retreat.
When does this apply?
This pays off when you need the saved time for something important, such as an attack. First check which pieces will remain: if you give up a piece you need for your attack, you throw the attack away.
Step 5 of 6
New position, same idea
A new position. Once again, one of your pieces is attacked.
The pawn on e5 attacks your knight on d4. What do you do?
Arrow keys move the focus across the squares. Enter or Space selects a piece and moves it to a highlighted square. Escape cancels the selection.
Choose a move from a list
Position as a list
White
- King g1
- Rook d1
- Knight d4
- Pawn a2
- Pawn c3
- Pawn f2
- Pawn g2
- Pawn h3
Black
- King g8
- Rook b2
- Knight c6
- Pawn a6
- Pawn b7
- Pawn e5
- Pawn f7
- Pawn g7
- Pawn h7
Step 6 of 6
Nimzowitsch and today
Source
Nimzowitsch warns against being too eager to exchange. He lists only a few cases where an exchange is right: to occupy or open a file without losing time, to remove a defender, and to avoid losing time by retreating when the saved time can be put to good use. He says it is well known that a knight on f6 protects the whole kingside and argues that every defender should be removed. The text and positions are newly written for the course.
- My System, chapter 5 (in German): “Der Abtausch” (original text not yet published)
Today’s view (editorial note)
Nimzowitsch already wrote that simplifying helps the player with more material. That still holds today. The idea in this lesson is now often called “removing the defender”.