Benko Gambit

Strategic Summary & Main Idea

The Benko Gambit gives up a queenside pawn on move three and asks for nothing in the short term: no attack, no immediate initiative. It asks for two open files, a and b, and a bishop on g7 aimed down the long diagonal — compensation that only pays out in the endgame. The position after 3...b5 measures +0.70, and the main accepted line, fourteen moves later, still measures +0.72. The engine does not see the compensation; decades of practical results do. This entry publishes both sides of the argument, and the finding is that declining with 4.Qc2, which looks prudent, measures −0.41.

The pawn structure this opening produces

The Benko is the most structural gambit there is: there is no tactic anywhere in the price of the pawn. After 4.cxb5 a6 5.bxa6, Black has the a- and b-files open against White's a2 and b2 pawns, a bishop on g7 eyeing d4 and b2, and a white central majority that cannot advance without opening lines for Black's own rooks. Black's plan is simple and repeats in nearly every game: ...Bxa6 or ...g6 and ...Bg7, castle, ...Nbd7, ...Qa5 and rooks to a8 and b8. From there Black presses a2 and b2 indefinitely, and White needs e4-e5 or f4 to justify the extra pawn. The structure explains why White often gives the pawn back with 5.b6 or never takes it at all: keeping the material means accepting a position where every black piece has a job and no white piece has counterplay. The second feature is the d5 pawn: it locks the centre, and while it stands Black plays without risk of being blown off the board. When it advances or falls, the Benko is over and a different game begins.

Main Variations of the Benko Gambit

Evaluations measured by us with Stockfish 19, depth 22, on 14/09/2026.

Frequently asked questions

Is the Benko Gambit sound?

The engine says no: the accepted main line measures +0.72 after fourteen moves, essentially the same as the +0.70 starting position. The Benko's compensation is long-term — open files and permanent pressure on a2 and b2 — the kind of advantage an opening evaluation captures poorly. What the number does say safely is that there is no immediate compensation; the rest is decades of practical results.

Should White accept the pawn?

Accepting and returning it quickly is the most efficient choice: 5.b6 measures +0.50 and dismantles Black's plan before the files open. Declining with 4.Nf3 measures +0.52 and transposes to a Benoni. What not to do is decline with 4.Qc2, which looks like the most natural move on the board and measures −0.41 — Black recovers the pawn with tempo and stands better.

Why does White's king walk to g2?

Because in the main line Black trades the a6 bishop for the one on f1, and the recapture Kxf1 forfeits castling. The Kg1-g2 manoeuvre is how the king finds safety without spending the rook, and it has been theory since the 1970s. It is also the best portrait of the gambit: White wins a pawn and spends four moves tidying up his own king.

Guides on this opening

• Benko Gambit: how to play the queenside pawn sacrifice, and what the engine charges for it

Common Mistakes & Where Most Amateurs Go Wrong

• 01 Skipping ...a6 and fianchettoing straight away. Without the open file Black is simply a pawn down with no structural compensation: the position rises from +0.70 to +2.14. The line: 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 g6 5.Nc3 Bg7 6.e4 O-O 7.Nf3 d6 8.Be2 Nbd7 9.O-O +2.14