J) 4....Nxe4 5.Qxd4 Nf6 6.Bg5?! Nc6 7.Qh4

Position after 6.Bg5?! Nc6 7.Qh4

   Black's best retreat is clearly 5....Nf6, when 6.Bg5?! has long been the standard move. After 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3 Nxe4 5.Qxd4 Nf6 6.Bg5?! (6.O-O?! d5! =+) 6....Nc6 7.Qh4, Black normally transposes to he standard line with 7....Be7 8.Nc3. But Black has several ways to make White miserable. Best therefore is 6.Nc3!, covered in Line K and following. 

J1) 7....Qe7+!? puts an awkward question to White's King and points up one of the main reasons to prefer 6.Nc3, when Be3 can block Queen checks along the e-file without loss of time.

J2) 7....Bb4+ 8.Nc3 Qe7+ 9.Kf1 Bxc3 10.bxc3 d6 11.Nd4 Be6?! (11....Nxd4) 12.Bb5 Kd7 13.Nxc6?! bxc6 14.Bxc6+? Kxc6 15.Qa4+ Kb7 16.Rb1+ Kc8 17.Bxf6 Qxf6 -+ Steenstup--Pilgaard, Copenhagen 1992.

J3) 7....d5! 8.Bxf6 (8.Bb5 Qe7+ 9.Kd1 Qd6 10.Re1+ Be7 =+ Dellenbach--Kervaire, Correspondence 1986, or 8.Bd3?! Bb4+!? 9.c3 Qe7+ 10.Be2 =+ Pilgaard--Christensen, Copenhagen 1989, or 8.Bd3?! Nb5! Tholefson--Torre, Dimock Theme Tournament 1924 ) 8....gxf6 9.Bb3 (9.Be2 f5!? 10.Qh5 Qf6 11.Nc3 Be6 12.O-O-O d4 13.Nb5 O-O-O =+ Gneiss--Gretarsson, Velden 1996) 9....Qe7+ (9....Be6 10.Nc3 Bb4 11.O-O-O Bxc3 12.bxc3 Qe7 13.Bxd5 O-O-O = Tartakower--Shories, Barmen 1905) 10.Kd1 a6 (10....Bd7!? 11.Bxc6 is similar) 11.Re1 Be6 12.Bxc6+ bxc6 13.Nd4 Kd7 14.f4 c5 15.Nf5 Qd8 16.Qh5 Kc6 17.Nd2 d4 =+ 18.Ng3 Bd6?! 19.c4 Kb6 20.f5 Bd7 21.Nge4 Ba4+ 22.b3 Bc6 23.b4 Be5 24.Nxc5 d3 25.Rb1 Qd4 26.Qh3 Rad8 27.Re3 Bf4 28.Rxd3 Qf2 29.Kc2 Bxd2 30.Kb3 Rxd3+ 31.Nxd3 Qd4 32.Nb2 Re8 33.Nd1 Re4 34.c5+ Kb7 35.a3 Qc4+ 36.Kb2 Re2 0-1 Shtanchaev--Varavin, Russia 1996.

Line K>>>