ecocodes

Study notes

Short pieces that read the whole list at once: how its 3,865 lines are spread, where they go deep, and what happens on the board when names are given. Every number is counted from the list itself.

  1. How the 500 ECO codes are organisedFive letters, a hundred numbers each, and what the Lichess opening list files under them.
  2. Which first move leads to which ECO volumeTwenty possible first moves, very unevenly shared out between five volumes.
  3. The longest named lines in the opening listFrom one move to 36 plies: how far names reach into the game.
  4. Gambits by the numbersWhat the board says when a gambit gets its name.
  5. Transpositions: one position, several move ordersOpenings are named after positions, and positions can be reached in more than one way.
  6. Castling in named opening linesMost names are given before the king moves. The exceptions are revealing.
  7. How to name an opening from a game’s movesRead the game backwards until a named position appears.