Two Knights Defense, Fried Liver Attack

The Fried Liver, or Fegatello, Attack punishes the recapture 5...Nxd5 by giving up the knight on f7. The idea is that the d5-knight, lacking pawn support, becomes a target once the black king is pulled forward. After 6...Kxf7, by far the most common reply, 7. Qf3+ forces 7...Ke6, since other king moves either lose the d5-knight or, after 7...Kg8, allow mate following 8. Bxd5+. White continues with 8. Nc3, and Black shields the pinned knight with 8...Nb4 and ...c6. The natural 9. a3 lets Black take material with 9...Nxc2+, so 9. Bb3, 9. Qe4 and 9. O-O are considered stronger.

Known since Polerio's play before 1606, the attack has not been proven decisive, but engines give White a clear advantage and White scores heavily in online games, as the defense is difficult to find at the board, particularly at fast time controls. Of the queen moves 6...Qf6 and 6...Qh4, the latter fares better for Black. Partly because of this line and the Lolli Attack, 6. d4, Black usually prefers 5...Na5 to 5...Nxd5.