Chess Openings
Every opening here comes with its main line on a board you can step through, statistics from club games at 1200–2200, a free PGN of the full variation tree, and aspaced repetition trainer that drills it into you. New to openings? Start with the opening basics guide.
Queen's Gambit AcceptedECO D20–D29 · 2 variations · 58 named lines
Queen's Gambit DeclinedECO D02–D69 · 10 variations · 198 named lines
Slav DefenseECO D10–D19 · 2 variations · 52 named lines
30 more opening families are on the way. Thetrainer already covers all of them.