Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. Ng5/4...d5/5. exd5/5...Nd4/6. c3/6...b5/7. Bf1/7...Nxd5/8. Ne4/8...Qh4/9. Ng3

Two Knights Defence:Fritz variation
a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h
Position in Forsyth-Edwards Notation (FEN) r1b1kb1r/p1p2ppp/8/1p1np3/3n3q/2P3N1/PP1P1PPP/RNBQKB1R b
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Nd4 6. c3 b5 7. Bf1 Nxd5 8. Ne4 Qh4 9. Ng3

Two Knights Defence:Fritz variation

9 Ng3
The Knight comes to add protection against the Black Queen. Black's Knight on d4 is now vulnerable, but Black having more development can aggressively create threats. The choice is to move the d4 Knight or create further complications, for a long time 9...Bg4 was consider good but later analysis has indicated that with correct play White has a clear plus.

Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 b5 6.Bf1 Nd4 7.c3 Nxd5 8.Ne4 Qh4

	9	10	11	12
	Ng3 Nc6	Bxb5 Bb7	O-O O-O-O		∞
	... Ne6	Bxb5 Kd8	d4 Bb7	dxe5 Kc8	+/-
	... Bb7	cxd4 O-O-O	Be2 Nf4	O-O Rxd4	+/-
	... Bg4	f3 e4	cxd4 Bd6	Bxb5+ Kd8	+/-

References

• Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.