Chess Openings Lab
a8b7c6d5e4f3g2h1

English Opening: Jaenisch Gambit

The Jaenisch Gambit is 1...b5, offering a wing pawn on move one. White can simply take with 2.cxb5 and keep the pawn, so the gambit is dubious; Black's hope is quick play on the long diagonal and open a- and b-files.

Moves
1.c4 b5
ECO
A10
Engine
+0.90 · a clear edge for White (Stockfish 17.1, depth 20)
Played
363 games in our lichess sample
White scores
53.3%

Key ideas for both sides

White

  • 2.cxb5 takes the pawn. After ...a6 3.e3, White is ready to recapture on b5 with the bishop.
  • 4.Bxb5 keeps the extra pawn and develops at the same time.
  • Nf3, castling and d4 finish development, and White has an extra pawn and a solid center.
  • Against ...e5 and ...e4, put the knight on d4 and keep the center under control.

Black

  • ...a6 offers a second pawn, Benko style, to open the a- and b-files.
  • ...Bb7 aims at the long diagonal and the g2 pawn.
  • ...e5 and ...e4 gain central space, as the top engine line shows.
  • If White declines with 2.d4 or 2.Nf3, ...bxc4 wins back the c4 pawn.

Plans and pawn structure

After 2.cxb5, White keeps the pawn and develops. Black's compensation is the open files and the long diagonal, but White's simple plan of e3, Bxb5, Nf3 and castling leaves Black with nothing concrete. Black's best is fast central play with ...e5 and ...e4. White should just develop and keep the extra pawn.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.90: a clear edge for White. Its three top choices for White:

  1. +0.90 2.cxb5 a6 3.e3 axb5 4.Bxb5 e5
  2. +0.25 2.d4 bxc4 3.e4 Ba6 4.Nc3 e6
  3. +0.24 2.Nf3 bxc4 3.e4 e6 4.Bxc4 d5

Pawns, from White's side.

How it scores on lichess

363 rated lichess games reached this position; White scored 53.3%.

under 120058.3%
1200–159958.2%
1600–199951.5%
2000 and up49.4%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

How to play against it

As White, take with 2.cxb5 and play e3 to support b5 with the bishop. Do not chase Black's pieces; develop and castle. As Black, if you play this, know that White can keep the pawn with simple moves.

Questions

What are the moves of the English Opening: Jaenisch Gambit?

The English Opening: Jaenisch Gambit starts 1.c4 b5. Its ECO code is A10.

Is the English Opening: Jaenisch Gambit good for Black?

Stockfish 17.1 rates the position +0.90 at depth 20, which is a clear edge for White. In 363 lichess games from our sample, White scored 53.3%. A surprise weapon at best; White keeps a clear edge with simple development.

What is the main idea of the English Opening: Jaenisch Gambit?

Black offers a pawn for open lines on the queenside. White takes with 2.cxb5 and keeps the extra pawn with e3 and Bxb5.

What should White play next?

The engine's first choice is cxb5, with d4 and Nf3 close behind. 2.cxb5 takes the pawn, and e3 next lets the bishop defend b5.

Updated October 2026. Sources and method.