ecocodes

Which opening is this?

Play moves on the board or type them in. The finder replays them and names the deepest position on the way that appears in the list of 3,865 named lines, with its ECO code.

a1b2c3d4e5f6g7h8

From the starting position

No move played yet. The list starts with 20 different first moves; this is how many of its lines begin with each, and the named position each one reaches straight away.

MoveLinesNamed position after it
2,032B00 King’s Pawn Game
1,333A40 Queen’s Pawn Game
202A10 English Opening
109A04 Zukertort Opening
29A00 Van Geet Opening
27A00 Polish Opening
27A02 Bird Opening
21A00 Hungarian Opening
20A00 Grob Opening
15A01 Nimzo-Larsen Attack
9A00 Kádas Opening
7A00 Ware Opening
6A00 Van’t Kruijs Opening
6A00 Barnes Opening
5A00 Anderssen’s Opening
5A00 Mieses Opening
4A00 Sodium Attack
4A00 Clemenz Opening
3A00 Amar Opening
1A00 Saragossa Opening

How to use it

Click a piece, then the square it should go to. Or type the moves of your game into the box, with or without move numbers (1.e4 c5 2.Nf3 and e4 c5 Nf3 both work, as do O-O and 0-0). Every move is checked for legality; an illegal or unreadable move stops the reading there and is shown in red.

The answer is the last position in your moves that carries a name in the list. That is the convention the list itself recommends: read the game backwards until a named position turns up. Because positions are compared rather than move sequences, a different move order into the same position is recognised. Under the board, the moves that keep you inside named territory are offered as buttons, with the number of named lines that pass through each resulting position.

The finder only names positions. It does not judge moves, suggest what to play or say how often an opening is played; the list contains no game results. Opening names are those of the lichess-org/chess-openings list (CC0).