Cochrane Gambit, Bishop Check Line

After 4...Kxf7 in the Cochrane Gambit, the Bishop Check Line develops the king's bishop with tempo on the a2–g8 diagonal, aiming at the uncastled king before Black can consolidate the extra piece. Engines consider this premature and give Black a clear advantage. The best-regarded answer is 5...d5, which blocks the diagonal by returning a pawn. Recapturing on d5 would cost White much of the attacking momentum, so the center opens on Black's terms. The alternatives 5...Be6 and 5...Ke8 are also sound, though they let White probe the king position further.

Online practice differs from engine preference. 5...Be6 is chosen in about half of all games and gives Black the best results, inviting an exchange of light-squared bishops that blunts White's pressure. 5...d5 and 5...Ke8 follow in popularity and lead to nearly even scores. Overall Black wins slightly more often than White, and draws are rare, which reflects how hard the exposed king is to defend over the board.