The opening trainer
Your opponent doesn't play the theory. Punish them anyway.
Below 1800, almost nobody follows the book past move five. Learn your opening one variation at a time, then drill the deviations players at your level actually play — mined from real games, and every refutation checked by an engine.
Learn
One path per opening
A course is a path of variations. Each node runs three ways: watch it played and explained, play it yourself, then answer a position from the middle of it with no moves shown.
Punish
The mistakes that actually happen
For every position in your repertoire we know what players at your rating really play. The frequent, refutable ones become puzzles — with the frequency printed on them.
Remember
Reviews by position
A review card is one position, not a whole variation. A position taught in three lines is reviewed once — no avalanche, no re-drilling what you already know.
Start with an opening
As White
The Italian Game
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5
A complete 1.e4 repertoire built on 3.Bc4: the quiet Giuoco Piano, the sharp Two Knights, and the answer to everything Black actually tries below 1800.
As Black
The Caro-Kann
1.e4 c6 2.d4 d5 3.Nc3 dxe4
The solid answer to 1.e4: a good bishop, a sound structure, and no memorised disasters. Covers the Advance, the Exchange, the Panov and the Two Knights.