Milady-de-Winter vs magnuscarlsen

Black chose 21...b5, pushing the b‑pawn two squares into the line of White's queen on c4. The move leaves the pawn on b5 en prise; White can immediately capture with 22.Qxb5, winning a pawn and simultaneously attacking the undefended Black queen on a5. The pawn push also does nothing to address Black's most urgent problems – the queen on a5 is still undefended, and White threatens the c5 pawn and the e5 pawn.

The engine recommends 21...Bb5 (bishop from c6 to b5). This move attacks the White queen on c4, forcing it to move and thereby eliminating the tactical shot 22.Qxb5. By gaining a tempo on the queen, Black keeps material balance, preserves the pawn structure, and retains the threat of ...Qxa2 or ...Qe1. In contrast, 21...b5 concedes a pawn and gives White a clear, forcing continuation, which is why the engine marks it as a missed opportunity.

Create Threats Before Making Pawn Moves: If a piece can immediately attack an opponent's piece, use it to gain a tempo. Pushing a pawn into an opponent's line without creating a counter‑threat often loses material. Always ask, "What does my opponent gain after this move?" before committing pawn pushes.