Openings
What is a ECO in chess?
- Opening
- Plans
- Move Order
ECO is a chess abbreviation. In practical terms, it refers to the Encyclopaedia of Chess Openings (ECO), a standard and comprehensive chess opening reference. Also ECO code, a classification system for openings that assigns an alphanumeric code from A00 to E99 to each opening. If you see it in a database, book, or tournament page, treat it as shorthand and check the surrounding context.
What to look for on the board
- Development, center control, and king safety.
- The pawn break each side wants.
- Whether a move creates a familiar structure.
ECO FAQ
What is a eco in chess?
ECO is a chess abbreviation. In practical terms, it refers to the Encyclopaedia of Chess Openings (ECO), a standard and comprehensive chess opening reference. Also ECO code, a classification system for openings that assigns an alphanumeric code from A00 to E99 to each opening. If you see it in a database, book, or tournament page, treat it as shorthand and check the surrounding context.
How do you spot a eco on the board?
Look for: Development, center control, and king safety.; The pawn break each side wants.; Whether a move creates a familiar structure..
What is the most common mistake with a eco?
Memorizing the term while missing the plan behind the structure.
How do you get better at using a eco?
For any opening term, learn the plan and pawn structure, not just the move order.
Train this pattern on your own games
Reading a definition is not the same as spotting the pattern with a clock running. Chessiro's free game review runs Stockfish 18 over every move you play, names the concept behind each mistake, and turns the positions where it cost you into training puzzles. You can also see the idea in action in the classic games collection, where the greatest players in history demonstrate it.
Related terms
Free game review
See where eco decides your games
Chessiro reviews your games with an AI coach that names the concept behind every mistake, then drills you on the exact positions where it happened until you stop repeating them.
