About Blundr
Opening training for the moment your opponent leaves the book
Blundr is a chess opening training platform for players who want more than a memorized move list. It connects real opening relationships to interactive practice and useful review.
Understand the opening
Explore plans, structures, branches, and common mistakes so an opening becomes a set of decisions you can recognize.
Practice the opening
Train the positions behind your repertoire, review the moves you miss, and build recall that transfers to games.