Chess Opening Theory/1. e4/1...d5/2. exd5/2...Qxd5/3. Nc3

Mieses-Kotrč variation
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) rnb1kbnr/ppp1pppp/8/3q4/8/2N5/PPPP1PPP/R1BQKBNR
	Moves: 1.e4 d5 2.exd5 Qxd5 3. Nc3
	ECO code: B01
	Parent: Mieses-Kotrč variation

3. Nc3

White develops with tempo against Black's queen. Black's queen now must find a safe square: ideally one from which she may not be kicked again straight away.

3....Qa5 is the mainline. From a5 the queen cannot be attacked immediately, she can pin the knight should White dare to advance their d pawn, and she can later move to b6 to target the b2 pawn. From a5 she supports e5. This is considered the sharpest variation.

The principal alternatives are 3...Qd8 and 3...Qd6.

3...Qd8 un-develops the queen. She is now very safe but her scope is greatly limited, and Black will presumably at some point have to spend some tempo to bring her out again. It has the reputation for being the safest and least theoretical continuation. Its most vocal advocate has been John Bartholomew.

3...Qd6 was pioneered by Grandmaster Sergei Tiviakov and others. The queen is much more active here than back on d8 but a mite more vulnerable. Black must soon play c6 or a6 to prevent Nb5 to kick the queen.

Bad moves

3...Qe6+!? and 3...Qe5+!? to check White's king are common amateur tries, but they do not accomplish much for Black. 4. Be2 and White has developed another piece, and Black's queen is blocking in their e pawn and so will probably have to move again.

One idea behind 3...Qe6+ 4. Be2 is that Black wants to target the weakened g2 pawn. However, to pursue it is folly and White should be happy to give it up: 4...Qg6 5. Nf3 Qxg2?! 6. Rg1 Qh3 and White's has four pieces developed, they're about to play d4, and their rook is well positioned on the half open g file, whereas Black has only developed their queen, who White can kick again with Rg3.

Most other possible third moves blunder the queen, as White either directly controls the squares (b5, c4, d3 by the bishop, e4 and d5 by the knight, f3 and h5 by the queen) or they afford White further tempo. A quick survey of the foil to the remaining moves:

3...Qd7?! is difficult to immediately refute, but Black's position looks awkward with their light-squared bishop blocked and the need to be vigilant in case the queen becomes pinned to the king.
3...Qd4? and Nf3 scores tempo.
3...Qf5? runs into d4 & Bd3.
3...Qg5? allows d4 with a discovered attack
3...Qc5? and Qe5+?! will be kicked again after d4 and/or Nf3.
3...Qc6?? and Bb5 pins it to the king, winning the queen.

Theory table

1. e4 d5 2. exd5 Qxd5 3. Nc3

	3	4	5	6	7	8	9	10
Mieses-Kotrč variation	... Qa5	d4 Nf6	Nf3 c6	Bc4 Bf5	Bd2 e6	Nd5 Qd8	Nxf6+ gxf6		±
Leonhardt gambit	... ...	b4 Qxb4	Rb1 Qd6	Nf3 Nf6	d4 g6	Bc4 Bg7	O-O O-O		⩱
	... ...	... ...	Nb5 Qa5	Bc4 c6?	Bxf7+ Kxf7	Qh5+ g6	Nd6+ exd6	Qxa5	+-
Valencian variation	... Qd8	d4 Nf6	Nf3 Bg4	h3 Bxf3	Qxf3 c6	Be3 e6	Bd3 Nbd7	O-O Bd6	±
Gubinsky-Melts variation → Bronstein variation	... Qd6	d4 Nf6	Nf3 a6	g3 Bg4	Bg2 Nc6	O-O O-O-O			±
	... Qe5+?	Be2 Qg5?	Nf3 Qxg2	Rg1 Qh3	Rg3 Qe6	d4 Nf6			±

Wikipedia has related information at Scandinavian Defence.

References

Anatoli Karpov - Bent Larsen 1979

3. Nc3

Bad moves

Theory table

References

See also