Italian Game, Two Knights Defense, Polerio Defense

The Polerio Defense begins after 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5. White has captured on d5 and still pressures f7. Instead of recovering the pawn with the f6-knight, Black moves the c6-knight to a5, where it attacks White’s bishop on c4.

The point is to gain a tempo against the bishop and organize recovery of the pawn later. Gaining a tempo means improving a piece while forcing the opponent to spend a move responding. The knight on a5 looks far from the center, but its immediate attack prevents White from continuing the attack without first deciding where the bishop belongs.

The choice also avoids 5...Nxd5, the recapture that allows the Lolli Attack and the Fried Liver sacrifice. Black accepts a temporary pawn deficit in order to develop quickly and challenge White’s center. White tries either to keep the advanced pawn or use it to delay Black’s coordination.

What each side must watch

• White needs a bishop retreat that does not surrender the pressure without compensation.
• Black must recover the pawn without leaving the a5-knight outside the game.
• Both kings remain in the center, so opening lines may matter more than counting pawns.