Not that easy

My previous post covered a line in the Teichmann defense : 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Bg4 6.h3 Bh5 7.g4 Bg6 8.Ne5 with black now attacking white's outpost on e5 with 8...Nfd7 or the more natural 8...Nbd7.

We learned that white gets a small advantage after 8...Nfd7 and that black can obtain equality after 8...Nbd7 9.Qf3 c6 10.Nxg6 hxg6 11.g5.

Now there is also the line 8...Nbd7 9.Qf3 e6. Houdini, at a depth of 22, sees a tiny white advantage but rates both 10.Qxb7 and 10.Nxg6 the same. To determine which one is best, let's look first at 10.Qxb7 (diagram).

a/ 10...Nxe5 11.dxe5
...a1/ 11...Nd7 12.Bb5 Rb8 13.Qxa7
......a1a/ 13...Qh4+ 14.Qf2 (=)
......a1b/ 13...Bb4 14.Bxd7+ Kxd7 15.Be3 (+=)
......a1c/ 13...Be7 14.Be3 (+=)
......a1d/ 13...Ra8 14.Qf2 (+=)
......a1d/ 13...Rxb5 14.Nxb5 Bb4+ 15.Bd2 Bxd2+ 16.Kxd2 Nxe5 17.Kc3 (+=)
...a2/ 11...Rb8 13.Bb5 Nd7 transposing to a1.

b/ 10...Rb8 11.Qxa7
...b1/ 11...Nxe5 12.dxe5 Nd7 13.Bb5 transposing to a1.
...b2/ 11...Ne4 12.Nxd7 Kxf7 13.Qa4+ c6 14.Qa7+ (=)
...b3/ 11...Ra8 12.Qb7 (=)

The lines after 10.Nxg6 hxg6 11.Bg2 (diagram) are quite different :

c/ 11...c6 12.Rf1 Qe7 13.Bg5 (+=)

d/ 11...Bd6 12.00 00 13.Qxb7 (=)

e/ 11...Be7 12.Qxb7 (+=)

f/ 11...Bb4 12.00 (+=)

g/ 11...c5 12.Be3 (=)

h/ 11...Rb8 12.Rf1 (+=)

i/ 11...Qc8 12.Rf1 (+=)

j/ 11...Nb6 12.g5 (+=)

So overall, it seems that the continuation 10.Nxg6 hxg6 11,Bg2 offers the attacker better chances than 10.Qxb7.