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Two Knights Defense, Fried Liver Attack, Lolli Attack, Morphy Defense Analysis

Care for some Fried Liver? ...or a Lolli-pop?

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5* d5 5.exd5 Nxd5!? 6.Nxf7!?

*a) 65/97    +0.13    4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Bd3 Nd5 9.Nf3 Bd6 10.Nc3 Nf4 11.0-0 Nxd3 12.cxd3 0-0 13.Re1 Re8 14.Ne4 c5 15.b3 Bf8 16.Ba3 Nc6 17.Rc1 Nb4 18.Bxb4 cxb4 19.Nc5 Qd5 20.d4 Bg4 21.h3 Bxf3 22.Qxf3 Qxd4 23.Rc4 Qxd2

b) 4.d3 74/109        +0.00    4...Bc5 5.c3 d6 6.Bg5 h6 7.Bh4 a6 8.Nbd2 g5 9.Bg3 Ba7 10.0-0 0-0 11.Bb3 Kg7 12.Nc4 Ne7 13.h3 Ng6 14.Ne3 Bxe3 15.fxe3 a5 16.Bc2 Be6 17.a4 g4 18.hxg4 Nxg4 19.Qe2 h5 20.b4 c6 21.Be1 axb4 22.cxb4 f5 23.a5 Qe7 this is the more popular line...

c) +0.00/68 4.Qe2 Bc5 5.d3 0-0 6.0-0 d6 7.Bb3 h6 8.a4 a5 9.Be3 Bxe3 10.fxe3 Be6 11.Bxe6 fxe6

d) +0.00/68 4.Nc3 Nxe4 5.Nxe4 d5 6.Bd3 dxe4 7.Bxe4 Bd6 8.0-0 0-0 9.Re1 Bg4 10.c3 Kh8

e) 4.d4 exd4 5.0-0 (5.e5 +0.00/63 5...d5 6.Bb5 Nd7 7.0-0 Be7 8.Bxc6 bxc6 9.Nxd4 Nb8 10.Qf3 0-0 11.c4 f6) 5...Nxe4 6.Re1 d5 7.Bxd5 Qxd5 8.Nc3 now +0.00/60 8...Qa5 9.Nxe4 Be7 10.Bg5 0-0 11.Bxe7 Nxe7 12.Nd6 Nc6 13.Nxc8 Raxc8 14.Nxd4 Nxd4 15.Qxd4 h6 16.Qe4 Rcd8 17.Qxb7 Rb8 18.b4 Rxb7 19.bxa5 Rd8 20.Rab1 Rxb1 21.Rxb1 Rd5 22.Rb8+ Kh7 23.Kf1 Rxa5 24.Rb7 Rxa2 25.Rxc7 Kg6 26.Ke2 Kf6 27.g3 Ra1

The analysis below will show the main line to be 6...Kxf7 7.Qf3+ Ke6 8.Nc3 Nb4 9.0-0! c6 10.d4 Qf6 11.Qe2 Ke7 12.dxe5 Qg6 13.Ne4 Bf5 14.f3 Kd8 or Ke8, where white has an advantage.

Note the recent and older sections to this analysis. Some of the older analysis is less reliable. Analysis was started with Stockfish_200407 but began gradually switching to use the latest release version. Note that Stockfish is currently gaining 50 ELO in performance per year. Attempts to reproduce these results several years later with the current version of Stockfish may produce different results.

Why play 6.Nxf7!?...? The only alternative is 6.d4 (Lolli Attack, below), where in certain lines we end up playing Nxf7 anyway: after 6.d4 best seems 6...Nxd4 or 6...Bf5

...The real question is why black plays 5...Nxd5!?, when after 5...Na5 6.Bb5+

6.d3 is playable but not best: 73/105     -0.19    6...h6 7.Nf3 e4 8.Nd4 (8.Qe2 Nxc4 9.dxc4 Bc5 -0.50/64 10.h3 0-0 11.Nh2 c6 12.0-0 cxd5 13.cxd5 Nxd5 14.Qxe4 Re8 15.Qf3 Be6) 8...Bc5 9.c3 0-0 10.0-0 Bg4 11.Qc2 Re8 12.h3 Bd7 13.Nd2 Bxd4 14.cxd4 b5 15.Bb3 Nxb3 16.Qxb3 exd3 17.Qxd3 Nxd5 18.Nf3 c6 19.Ne5 Ne7 20.Bd2 Bf5 21.Qc3 Qd6 22.Rac1 Be4 23.Rfe1 Bd5 24.Qc5 Qxc5 25.Rxc5 f6

6...c6 7.dxc6 bxc6 (Morphy Defense) there is more even play:

a) 92/118   2056:25:02  +0.13   8.Bd3 Nd5 9.Nf3 Bd6 10.Nc3 f5 11.Nxd5 cxd5 12.b4 Nc6 13.Bb5 Bb7 14.Bxc6+ Bxc6 15.Bb2 0-0 16.Nxe5 Re8 17.d4 Bxb4+ 18.c3 Bd6 19.0-0 Bxe5 20.dxe5 Rxe5 21.c4 Re7 22.cxd5 Qxd5 23.Qxd5+ Bxd5 24.Rfd1 Rd8 25.Bc3 Red7 26.Ba5 Rc8 27.a3 Kf7 28.h3 Rc2 29.Rd4 Be6 30.Rxd7+ Bxd7 31.Rd1 two thousand hours, kind of insane...

b) 75/95         0.00    8.Qf3 h6 9.Ne4 cxb5 10.Nxf6+ gxf6 11.Qxa8 Qd7 12.Qf3 Bb7 13.Qe2 Bxg2 14.Rg1 Rg8 15.d3 Nc6 16.Be3 Bf3 17.Qf1 Rxg1 18.Qxg1 Nd4 19.Kd2 e4 20.a3 exd3 21.Bxd4 Qxd4 22.Nc3 dxc2+ 23.Kxc2 Be4+ 24.Nxe4 Qxe4+ 25.Kd2 Qd4+ 26.Ke2 Qxb2+ 27.Kf3 Qb3+

c) 74/97         0.00    8.Be2 h6 9.Nf3 e4 10.Ne5 Bc5 11.0-0 Qd6 12.d4 Qxd4 13.Qxd4 Bxd4 14.Nc4 Nxc4 15.Bxc4 0-0 16.Rd1 Be5 17.Nc3 a5 18.h3 Bf5 19.a3 Rab8 20.Bb3 Rfe8 21.Be3 Be6 22.Bxe6 Rxe6 23.Rab1 Bxc3 24.bxc3 Rxb1 25.Rxb1 Nd5 26.Bd4 e3 27.f3 c5

Lolli Attack 6.d4

The proposed main line is a long computer run where we examine sidelines: +0.63/80    6...Nxd4

7.c3 b5 (7...f6 78/127        +0.83    8.cxd4 Bb4+ 9.Nd2 fxg5 10.0-0 c6 11.Ne4 0-0 12.Bxg5 Be7 13.Bxe7 Qxe7 14.Re1 Kh8 15.dxe5 Qxe5 16.Qd2 Qf5 17.Bxd5 cxd5 18.Ng3 Qf6 19.Rac1 Be6 20.Rc7 Rf7 21.Rc3 Re8 22.h3 h6 23.Re2 Bd7 24.Rf3 Rxe2 25.Qxe2 Qg6 26.Rxf7 Qxf7 27.Qe5 Kh7)

8.Bd3 (8.Bxd5 Qxd5 +0.13/54 9.f3 Be7 10.0-0 Qd8 11.cxd4 Bxg5 doesn't work for a white advantage, so white plays 8.Bd3)

8...h6 (50/77        +1.40    8...Nf4 9.Bxf4 exf4 10.Be4 Qxg5 11.Bxa8 Qe5+ 12.Kf1 Ne6 13.Bc6+ Ke7 14.Qe2 Qxe2+ 15.Kxe2 b4 16.Re1 Kf6 17.Kf1 Ba6+ 18.Kg1 Bd3 19.Rd1 Bxb1 20.Raxb1 bxc3 21.bxc3 Bd6 22.Kf1 g6 23.Ke2 h5 24.h4 a6 25.Rd5 Kg7 26.Ra5 Nc5 27.Kd2 Rd8)

9.Nxf7 Kxf7

10.cxd4 exd4 (10...Bb4+  76/138    +1.02    11.Bd2 Bxd2+ 12.Nxd2 Nf4 13.Be4 Qxd4 14.0-0 Rb8 15.Qc2 Qb6 16.Nf3 Re8 17.Rac1 c5 18.g3 Nh3+ 19.Kg2 Ng5 20.Nxg5+ hxg5 21.Rfd1 Bb7 22.Bxb7 Qxb7+ 23.Kg1 Kg8 24.Qxc5 g4 25.Qd5+ Qxd5 26.Rxd5 a6 27.Rc6 e4 28.Rxa6 e3 29.fxe3 Rxe3 30.Rd2 Rf8)

11.0-0 Rb8 ( a) 69/106    +0.86   11...c6 12.Nd2 Bd6 13.Nb3 Re8 14.Nxd4 Qh4 15.Nf3 Qf6 16.Bxb5 Kg8 17.Bc4 Be6 18.Qd4 Qxd4 19.Nxd4 Bf7 20.Nf3 a5 21.Rd1 a4 22.Be3 Rab8 23.b3 Nxe3 24.Bxf7+ Kxf7 25.Rxd6 Nc2 26.Rad1 axb3 27.axb3 Rxb3 28.Rxc6 Nb4 29.Rcd6 Rc3 30.Kf1 Re7 b)  69/99    +0.95    11...Nf6 12.a4 Bd6 13.axb5 Re8 14.Nd2 Bb7 15.Bc4+ Kf8 16.Nf3 Qd7 17.h3 Bd5 18.Bxd5 Nxd5 19.Qxd4 Rab8 20.Ra5 Rxb5 21.Qa4 a6 22.Rxa6 Nf6 23.Ra5 Rbb8 24.Qc2 Kg8 25.Nh4 Qe6 26.Nf5 Qe4 27.Qxe4 Rxe4 28.Nxd6 cxd6 29.Rd1 d5 30.Ra7 Reb4 31.Rd3 Rc8)

...and now 73/106    80:39:36       +0.72    12.a4 Nb4 13.Bxb5 Kg6 14.Nd2 Bd6 15.Re1 a6 16.Bc4 Bf5 17.Ra3 Re8 18.Rxe8 Qxe8 19.Nf3 Kh7 20.Nxd4 Rd8 21.Qe2 Qe5 22.Nf3 Qxe2 23.Bxe2 Be7 24.Ne5 Rd5 25.f4 Rc5 26.Bc4 Bf6 27.Rc3 Nd5 28.Bxd5 Rxd5 29.Rxc7 Bd8 30.Rc3 Bf6 31.Rc4 Bxe5 

Lolli Attack other move 6... choices for black:

a) +0.88/75 6...Bf5 7.dxe5 Ndb4 8.Bxf7+ Ke7 9.Bb3 Qxd1+ 10.Kxd1 now +1.07/83 10...a5 11.Na3 a4 12.Bc4 h6 13.Nf3 Rd8+ 14.Bd2 Kd7 15.Ke2 Kc8 16.Rhe1 Bg4 17.Bc3 Nd5 18.Bxd5 Rxd5 19.Nc4 Nd4+ 20.Bxd4 Rxd4 21.Ncd2 Rd5 22.h3 interesting alternate...

b1) 6...Be6  73/116    216:24:00        +1.05    7.0-0 Nxd4 8.Nxe6 fxe6 9.Nd2 Qd7 10.Qh5+ g6 11.Qxe5 Bg7 12.Qe4 0-0 13.c3 b5 14.cxd4 bxc4 15.Nxc4 Nb4 16.Be3 Qd5 17.Nd2 a5 18.Rfc1 e5 19.Qxd5+ Nxd5 20.dxe5 Bxe5 21.Rab1 Nxe3 22.fxe3 a4 23.Nf3 Bd6 24.Rc4 Rfb8 25.Rc2 Ba3 26.Kf2 Rb6  b2) +0.98/75 6...Be6 7.Nxe6 fxe6 8.0-0 Nxd4 9.Nd2 Qd7 10.c3 Nc6 11.Ne4 h6 12.a4 Nb6 13.Qh5+ Qf7 14.Be2 Nd5 15.Rd1 Be7 16.Qh3 0-0-0 17.Bg4 Kb8

c) +1.21/75 6...h6 7.Nxf7 Bb4+ 8.c3 Kxf7 9.Qf3+ Ke7 10.0-0 Be6 11.cxb4 12.Qg3 Kf7 13.Qxe5 Qf6 14.Qe4 Rhd8 15.Be3 Nf5 16.Nc3 c6 17.Bb3 Nxc3

d) 63/92        +1.36    6...Be7 7.Nxf7 Kxf7 8.Qf3+ Ke6 9.Nc3 Nxd4 10.Bxd5+ Kd7 11.Qh3+ Kd6 12.Qd3 c6 13.Bf4 exf4 14.Qxd4 Kc7 15.0-0-0 Kb8 16.Qe5+ Bd6 17.Qxg7 Qf8 18.Qxf8 Bxf8 19.Bf3 Kc7 20.Rhe1 Bf5 21.Ne2 Bd6 22.Nd4 Bd7 23.Rd2 Rad8 24.Ne6+ Bxe6 25.Rxe6 Rd7

e) 63/90        +1.39    6...f6 7.dxe5 Bb4+ 8.c3 fxg5 9.Bxd5 Be7 10.0-0 Nxe5 11.Re1 Nf7 12.Be3 0-0 13.Na3 a5 14.Nc4 Ra6 15.a4 Be6 16.Bxe6 Rxe6 17.Nxa5 b6 18.Nc4 Bf6 19.Qxd8 Nxd8 20.f3 h6 21.Nd2 Nb7 22.Ne4 Kf7 23.Bf2 Nd6 24.Nxf6 gxf6 25.Rxe6 Kxe6

f) 63/102        +1.55    6...g6 7.0-0 Be7 8.dxe5 Bxg5 9.Bxd5 0-0 10.Bxg5 Qxg5 11.f4 Qe7 12.Nc3 Rd8 13.Qf3 Bf5 14.Bxc6 Qc5+ 15.Rf2 bxc6 16.g4 Bxc2 17.Re1 Rd2 18.Qe3 Qxe3 19.Rxe3 Rad8 20.Rxd2 Rxd2 21.Re2 Rxe2 22.Nxe2 Bd3 23.Kf2 Bc4 24.a4 Be6 25.h3 a5

g) 63/95        +1.64    6...Bb4+ 7.c3 f6 8.dxe5 fxg5 9.Bxd5 Be7 10.0-0 Nxe5 11.Re1 Nf7 12.Be3 0-0 13.Na3 a5 14.Nc4 Ra6 15.a4 Be6 16.Bxe6 Rxe6 17.Nxa5 b6 18.Qxd8 Nxd8 19.Nb3 Nb7 20.Nd4 Rd6 21.b4 Bf6 22.Nb5 Rd7 23.Bd4 Bxd4 24.Nxd4 Ra8 25.h3 h6

h) 61/95        +1.73    6...Na5 7.Qf3 Be6 8.Nxe6 fxe6 9.Qh5+ g6 10.Bb5+ Kf7 11.Qf3+ Qf6 12.Qxf6+ Kxf6 13.dxe5+ Kg7 14.Bd2 Nb4 15.Ba4 Be7 16.f4 Rab8 17.Nc3 Nc4 18.0-0-0 Nxd2 19.Rxd2 Rhd8 20.Bb3 Rxd2 21.Kxd2 Kf7 22.g4 Rd8+ 23.Ke3 Bc5+ 24.Ke4 Nc6 25.Rd1 Rxd1

i) 57/97        +1.69    6...a6 7.Nxf7 Kxf7 8.Qf3+ Ke6 9.Nc3 Nxd4 10.Bxd5+ Kd7 11.Qg4+ Kd6 12.Qg3 Nxc2+ 13.Kf1 c5 14.Bg5 Qe8 15.Rc1 Nd4 16.Re1 Nf5 17.Qf4 exf4 18.Rxe8 h6 19.Bxf4+ Kd7 20.Re6 a5 21.Na4 Kd8 22.Rb6 Ra6 23.Rxa6 bxa6 24.Bd2 Bd7 25.Bxa5+ Ke8

j) 6...exd4 7.0-0 and now:

62/90    17:03:26        +1.76    7...Ne5 8.Re1 Ne3 9.Nxf7 Nxf7 10.fxe3 Be7 11.exd4 0-0 12.Rf1 Bf6

62/93    17:03:26        +2.50    7...Be7 8.Nxf7 Kxf7 9.Qf3+ Ke8 10.Bxd5 Qd6 11.Bf4 Qf6 12.Nd2 Rf8

62/103    17:03:26        +2.77    7...h6 8.Re1+ Nce7 9.Qh5 g6 10.Qf3 hxg5 11.Bxd5 Be6 12.Bxe6 fxe6

61/102    17:03:26        +2.64    7...Nce7 8.Re1 h6 9.Qh5 g6 10.Qf3 hxg5 11.Bxd5 Qd6 12.Bxf7+ Kd8

Summary: White has to know quite a lot of theory to counter creative attempts by black to complicate. It would seem that the lines below with 6.Nxf7 are more playable.

Fried Liver Attack 6.Nxf7

The main line continues: 6...Kxf7 7.Qf3+ Ke6 8.Nc3

8...Ncb4 other choices go nowhere with careful play by white, 8...Nd4 perhaps deserves a look, 8...Nce7 is surprisingly not effective:

1. 64/95        +2.32    8...Nd4 9.Bxd5+ Kd7 10.Qg4+ Kd6 11.Qd1 c6 12.Be4 Kc7 13.0-0 g6 14.d3 Bf5 15.Be3 h5 16.Qd2 Rc8 17.Ne2 Bd6 18.c3 Ne6 19.Bxf5 gxf5 20.f4 Rf8 21.fxe5 Bxe5 22.Nf4 Bxf4 23.Bxf4+ Nxf4 24.Qxf4+ Qd6 25.Rae1 Qxf4 26.Rxf4 Rcd8 27.d4 a5
2. 64/93        +3.17    8...Qd6 9.Bxd5+ Kd7 10.Ne4 Qg6 11.c3 Kd8 12.0-0 Be7 13.b4 Rf8 14.Qe2 Bg4 15.f3 Be6 16.Bxe6 Qxe6 17.Re1 a6 18.a4 Rf7 19.Nf2 Qf5 20.Ba3 Ke8 21.Ng4 Kf8 22.b5 Bxa3 23.bxc6 Bc5+ 24.Kh1 bxc6 25.Qc4 Bd6 26.Qxc6 Re8 27.Nf2 e4
3. 64/104        +3.19    8...Nce7 9.d4 c6 10.dxe5 Qe8 11.Be3 b5 12.Bb3 Qf7 13.Qh3+ Kxe5 14.Qg3+ Ke6 15.0-0-0 Kd7 16.Rhe1 Bb7 17.Bf4 Nf5 18.Nxd5 cxd5 19.Qf3 Bd6 20.Bxd5 Bxf4+ 21.Qxf4 Bxd5 22.Re5 Nd6 23.Qd4 Rhf8 24.Rxd5 Qf4+ 25.Qxf4 Rxf4 26.Rxd6+ Ke8 27.f3 Rf7
4. 64/101        +3.94    8...Qf6 9.Qxd5+ Ke7 10.d4 Nxd4 11.Ne4 c6 12.Qa5 b6 13.Qc3 Qg6 14.Bg5+ Kd7 15.0-0-0 Kc7 16.Rhe1 Kb7 17.Qg3 Qf5 18.f4 Ne6 19.fxe5 Nxg5 20.Nxg5 Qg4 21.Qxg4 Bxg4 22.Rd4 b5 23.Rxg4 bxc4 24.Rxc4 Rc8 25.Nf7 Rg8 26.Kd2 Rc7 27.e6 g5

white now has a) 9.0-0 or b) 9.Bb3, this analysis suggests 9.0-0 is best:

a) 9.0-0 c6 10.d4 Qf6 (+1.92/45 Kd7) 11.Qe2 Ke7 (+1.42/52 Kd7) 12.dxe5 Qg6 13.Ne4 Bf5 (13...Kd8 14.c3 Bf5 15.f3 transposes, +1.36/59 13...Bh3 14.Ng3 Bg4 15.f3 Bf5 16.Nxf5+ Qxf5 17.f4) 14.f3

April 2020 Stockfish_200407

80/141    694:38:19        +0.70    14...Kd8 15.c3 Na6 16.Bxa6 bxa6 17.Qxa6 Bc8 (+1.22/47 17...Kc7 18.c4 Bxe4 19.fxe4 Bc5+ 20.Kh1 Nb6 21.Qa5 Rhf8 22.Bd2 Be7) 18.Qa5+ Ke8 19.c4 Nb6 20.b3 Bf5 (20...Bh3 +1.02/73 21.Rf2 Bf5 22.Ng3 Kf7 23.e6+ Bxe6 24.f4 Bg4 25.f5 Qd6 26.Bb2 Re8 27.Re1 Rxe1+ 28.Qxe1 Be7 29.c5 Qd1 30.Qxd1 Bxd1 31.cxb6 axb6) 21.Ng3 Kf7 sliding to here we now see: +1.09/66 22.f4 Qe6 23.Re1 g6 24.h3 Nd7 25.Bb2 Kg8

76/117    235:58:09        +0.94    14...Ke8 15.a3 Na6 16.Bxd5 cxd5 17.Nd6+ Bxd6 18.exd6+ Kf8 19.Qe7+ Kg8 20.Qxb7 Re8 21.Bf4 Nb8 22.Qxd5+ Qf7 23.Qd2 h6 24.Rac1 Qc4 25.Rfd1 Kh7 26.Bg3 Rc8 27.Qd5 Bd7 28.Qxc4 Rxc4 29.b3 Rcc8 30.c4 Rhe8 31.Re1 g5 32.Rxe8 Rxe8 33.Re1 Rxe1+

74/125    154:23:32        +1.02    14...Kd8 15.c3 b5 16.Bb3 Na6 17.c4 bxc4 18.Qxc4 Nac7 19.Bg5+ Kc8 20.Rac1 Rb8 21.Qxc6 Qxc6 22.Rxc6 Rxb3 23.axb3 Kb7 24.Rfc1 h6 25.Bd2 Nb5 26.Nd6+ Bxd6 27.exd6 Nd4 28.Rc7+ Nxc7 29.Rxc7+ Ka6 30.Rxg7 Kb5 31.Be3 Ne6 32.Rf7 Bc2 33.b4 h5

note that 14...h5, 14...Nb6 and 14...h6 are rated as next best by the computer, and deserve a follow-up:

1. 73/117    209:19:04        +1.33    14...h5 15.Bg5+ Kf7 16.g4 Be6 17.f4 Bxg4 18.f5 Bxe2 19.fxg6+ Kxg6 20.Bxe2 Re8 21.a3 Rxe5 22.axb4 Nxb4 23.Bf3 Nxc2 24.Bf4 Rf5 25.Rac1 Rxf4 26.Bxh5+ Rxh5 27.Rxf4 Nd4 28.Ng3 Be7 29.Rg4+ Rg5 30.Rxd4 Bc5 31.Rxc5 Rxc5 32.Rd6+ Kh7 33.Ne4 Rb5
2. a) 73/119    209:19:04        +1.81    14...Nb6 15.Bb3 Kd7 16.Rd1+ Kc7 17.e6 Kc8 18.Nd6+ Bxd6 19.Rxd6 Re8 20.Bd2 N4d5 21.Re1 a5 22.Qf2 Ra6 23.Re5 Qf6 24.Rexd5 Nxd5 25.Qc5 Nc7 26.e7 b6 27.Rxf6 bxc5 28.Rxf5 Rxe7 29.Bc4 Rb6 30.b3 a4 31.Rxc5 axb3 32.axb3 Na6 33.Ra5 Nb4 b) Lc0_0.26.0_t60-4300 41/96    24:05:39     36,288k    418    +0.31    14. ... Nb6 15.Bb3 Kd8 16.a3 N4d5 17.g4 Be7 18.Ng3 Bd7 19.c4 Nc7 20.Bc2 Qf7 21.b3 Ne6 22.Be3 c5 23.f4 Nd4 24.Bxd4 cxd4 25.Rae1 Re8 26.e6 Qxe6 27.Qxe6 Bxe6 28.Rxe6 d3 29.Rxe7 Rxe7 30.Bxd3 g6 31.f5 gxf5 32.Nxf5 Rf7 33.Rd1 Kc7 need to adjust Lc0 setting CPuct to try a wider variety of moves...
3. 62/95    16:47:33        +1.61    14...h6 15.a3 Na6 16.Nd6 Kd7 17.Bxd5 Bxd6 18.exd6 cxd5 19.Qb5+ Kc8 20.Bf4 Qf7 21.Bg3 Nb8 22.b4 b6 23.Rfe1 a6 24.Qxb6 Qa7 25.Qxa7 Rxa7 26.Rad1 Rd7 27.Rxd5 Bg6 28.a4 Re8 29.Rc5+ Kb7 30.Rxe8 Bxe8 31.b5 Bf7 32.c4 Kb6 33.Rc7 Be6

b) 9.Bb3 c6 10.a3

April 2020 Stockfish_200407

78/122        +0.52    10...Qf6 11.Qxf6+ gxf6 12.axb4 Bxb4 13.Nxd5 cxd5 14.c3 Bc5 15.d4 exd4 16.cxd4 Bb6 17.0-0 Rd8 18.Rd1 Kf7 19.Bd2 a5

77/126    727:04:42        +0.25    10...Qf6 11.Qxf6+ gxf6 12.axb4 Bxb4 13.Nxd5 cxd5 14.c3 Bc5 15.d4 exd4 16.cxd4 Bb6 17.0-0 Rd8 18.Rd1 Kf7 19.Bd2 Be6 20.Ra4 Rac8 21.Re1 Bf5 22.Bc3 h5 23.h4 Rc6 24.Re3 Rd7 25.Ra1 Re6 26.Bd1 Kg6 27.Rg3+ Kh6 28.Rg8 Kh7 29.Rb8 Bg6

76/118    406:54:22        +0.41    10...Qf6 11.Qxf6+ gxf6 12.axb4 Bxb4 13.0-0 a5 14.d4 exd4 15.Nxd5 cxd5 16.Rd1 Bc5 17.c3 h5 18.h4 Rd8 19.cxd4 Bb4 20.Bf4 Bd7 21.Rd3 Bb5 22.Rg3 Bc6 23.Bd1 Rh8 24.Bc2 Rhg8 25.Rb3 Kf7 26.Bd1 Rh8 27.Bc7 Kg7 28.Bb6 Bd6 29.Bc5 Bc7

10...Na6  79/117        +0.65    11.Nxd5 cxd5 12.d4 Be7 13.c4 Qd6 14.0-0 e4 15.Qh5 Nc7 16.c5 Qc6 17.Bf4 Kd7 18.Bxc7 Kxc7 19.Qe5+ Kd8 20.Bxd5 Qg6 21.Bxe4 Qg5 22.f4 Qxe5 23.fxe5 a5 24.b3 Ra6 25.Rad1 g6 26.h3 Rf8 27.Kh2 Rxf1 28.Rxf1 Be6 29.Rf3 Bg8 30.Rc3 b6

c) 9.a3 Nxc2+ 10.Kd1 Nxa1 (10...Nd4 playable) 11.Nxd5 (11...c6 =) Qh4 is complicated and it is unclear if black can rescue the trapped knight on a1 in all lines of play 59/105    1:29:35         -1.27    12.d3 Kd6 13.h3 Be6 14.Ne3 e4 15.Nf5+ Kc6 16.Bxe6 exf3 17.Nxh4 fxg2 18.Nxg2 a5 19.a4 Bc5 20.Bc4 Rhf8 21.Nf4 Rae8 22.Bb5+ Kd6 23.Bxe8 Rxe8 24.Nh5 Rf8 25.Ng3 Kc6 26.Be3 Bxe3 27.fxe3 Rf2 28.Ne2 Nb3 29.Rg1 g6 30.Rg4 Rh2 31.Rc4+ Kd6

13 September 2019 Stockfish 190826 8...Nb4

69/108    226:23:40    4,879,347,158k    5,987k    +1.02    9.0-0 c6 10.d4 Qf6 11.Qe2 Ke7** 12.dxe5 Qg6 13.Ne4 Bf5*** 14.f3 Ke8* 15.a3 Na6 16.Bxd5 cxd5 17.Nd6+ Kd8 18.Bg5+ Kc7 19.Qd2 Rc8 20.Qxd5 Bxd6 21.exd6+ Kb8 22.d7 Qxg5 23.dxc8B Rxc8 24.Rfe1 Qg6 25.c3 Rc7 26.c4 Qb6+ 27.Kf1 Qf6 28.Rad1 Bc8 29.b4 b6 30.Rc1 Qb2 31.Qd3 Rd7 32.Qe3 Rd2 33.Qe5+ Qxe5 34.Rxe5 g6 35.c5 Nc7 36.cxb6 axb6 37.Re7 Rd7 38.Rce1 Ba6+ 39.Kf2 Kc8 40.Rxd7 Kxd7 41.Rd1+ Ke6 42.Rd8 Nd5 43.Re8+ Kf6 44.h4 h5 45.Rd8 Ke5 46.g4 hxg4 47.fxg4 Bd3 48.h5 gxh5 49.gxh5 Nf4

68/104    183:28:25    3,637,714,093k    5,507k    +0.96    9.0-0 c6 10.d4 Qf6 11.Qe2 Ke7 12.dxe5 Qg6 13.Ne4 Bf5 14.f3 Ke8 15.a3 Na6 16.Bxd5 cxd5 17.Nd6+ Bxd6 18.exd6+ Kf8 19.Qe7+ Kg8 20.Qxb7 Re8 21.Bf4 Nb8 22.Qxd5+ Be6 23.Qd2 h5 24.Rae1 h4 25.Re4 h3 26.g3 Nd7 27.Rfe1 Kh7 28.Kf2 Rhf8 29.b3 Bf7 30.Rxe8 Bxe8 31.Re7 a6 32.Ke2 Nf6 33.Kd1 Bc6 34.Be5 Re8 35.Rxe8 Bxe8 36.Qf4 Nd7 37.Bc3 Kg8 38.Qd4 Qf6 39.Kd2 Qf7 40.Kc1 Nf6 41.Kb2 Nd5 42.f4 Bd7 43.Qe4 Kf8 44.Bd4 Nf6 45.Bxf6 Qxf6+ 46.Qe5 Bg4 47.Qxf6+ gxf6 48.Kc3 Kf7

*14...Nb6 15.Bb3 56/96    5:21:08    171,646,644k    8,908k    +1.41    15...Kd8 16.Rd1+ Kc7 17.e6 Kc8 18.Nd6+ Bxd6 19.Rxd6 Re8 20.Bd2 N4d5 21.Re1 a5 22.Qf2 Ra6 23.Re5 Qf6 24.Rexd5 Nxd5 25.Qc5 Nc7 26.e7 b6 27.Rxf6 bxc5 28.Rxf5 Rxe7 29.Rxc5 a4 30.Bc4 Rb6 31.b3 Kd7 32.Bd3 axb3 33.axb3 h6 34.h4 Nd5 35.Ra5 Rb7

**11...Kd7 12.dxe5 a) 47/94    53:55     27,175,256k    8,399k    +1.45    12...Qg6 13.a3 Nxc3 14.bxc3 Nd5 15.Bd3 Qf7 16.c4 Ne7 17.Rb1 Qe6 18.f4 Nf5 19.g4 Nd4 20.Qd1 Kc7 21.f5 Qe8 22.Be3 Bc5 23.Kh1 Ne6 24.Qd2 Bxe3 25.Qxe3 Qe7 26.fxe6 Bxe6 27.a4 Rhe8 28.h3 b6 29.a5 Qc5 30.Qxc5 bxc5 31.Kg2 h6 32.Rb3 Rab8 b) 43/67    12:11     6,057,828k    8,285k    +1.24    12...Qf5 13.a3 Nxc3 14.bxc3 Nd5 15.Bd3 Qf7 16.c4 Ne7 17.Bb2 Ke8 18.e6 Bxe6 19.Rfe1 Bf5 20.Rad1 Rd8 21.Qe5 Qf6 22.Qf4 Qxb2 23.Qxf5 Qf6 24.Qa5 Rd7 25.Qxa7 Kf7 26.Bg6+ Nxg6 27.Rxd7+ Kg8 28.Qe3 h6 29.Rxb7 Kh7 30.g3 Bd6 31.Qe6 Qd4 32.Qf5 Rf8

***13...Kd8 64/115    72:42:53    1,994,646,981k    7,620k    +0.87    14.c3 Bf5 15.f3 Na6 16.Bxa6 bxa6 17.Qxa6 Bc8 18.Qa5+ Ke8 19.c4 Nb6 20.b3 Bf5 21.Ng3 Kf7 22.Re1 Kg8 23.Be3 Re8 24.Qxa7 Nc8 25.Qd4 h5 26.a4 h4 27.Nxf5 Qxf5 28.Bf2 Bb4 29.Re3 Ne7 30.a5 c5 31.Qd3 Rh6 32.a6 Ra8 33.a7 h3 34.g4 Qxd3  this could be a problem line needing additional work

Rybka4.1 this is older analysis

Section A: 8...Nce7

now [+1.16]  d=27 9.d4 c6 10.dxe5 Qe8 11.0-0 Qf7 12.Qd1 Kd7 13.e6+ Qxe6 14.Re1 Qf5 15.Bd3 Qf7

Section B: 8...Ncb4

[+0.37]  d=27  9.Bb3* c6 10.a3 Na6 11.Nxd5 cxd5 12.d4 Kd7 13.Qxd5+ Kc7 14.Qxe5+ Qd6 15.Qa5+ b6 16.Qc3+ Kb8 17.0-0 Qf6 18.Be3 Bd6 19.Qd2 Be6 20.Bxe6 Qxe6 21.Qe2 Kb7 22.c4 Rac8 23.Rac1 Rhf8 24.b4

[+0.26]  d=27  9.0-0 c6 10.d4 Qf6 11.Qe2 Ke7 12.Ne4 Qg6 13.a3 Bf5 14.f3 Na6 15.dxe5 Nac7 16.Kh1 h5 17.Nd6 Bxc2 18.Ne4 Ba4 19.f4 h4 20.f5 Qh5 21.Qd3 h3 22.g3 Bb5 23.Nd6 Bxc4 24.Qxc4

*chesslab.com lists one game played with this move, Tzounakas-Peramatzis, Athens 2008

21 March 2016 another look with Komodo 9.3 65:75:0

+0.46/44    9.Bb3 c6 10.a3 Na6 11.Nxd5 cxd5 12.d4 Kd7 13.dxe5 Kc7 14.Bf4 Nc5 15.Rd1 Ne6 16.Bxd5 Qe8 17.Be3 Be7 18.Qe2 Kb8 19.f4 g6 20.Rd2 Nc7 21.Bf3 Rf8 22.0-0 Be6 23.g3 Qc8 24.b4 Ne8 25.Rb1 Ng7 26.Qf2 Nf5 27.Bc5 Rd8 28.Rxd8 Bxd8 29.a4 Be7 30.Bxe7 Nxe7 31.Rd1 Nf5 32.g4 Ne7 33.Qh4

+0.20/44    9.0-0 c6 10.d4 Qf6 11.Qe2 Kd7 12.dxe5 Qf5 13.a3 Nxc3 14.bxc3 Nd5 15.Bd3 Qf7 16.c4 Ne7 17.Rb1 b6 18.Be4 Kc7 19.Rd1 Ng6 20.Bxc6 Kxc6 21.Qe4+ Kc7 22.Qxa8 Bc5 23.Qxa7+ Bb7 24.Be3 Ra8 25.Bxc5 Rxa7 26.Bxb6+ Kb8 27.Rd8+ Bc8 28.Bxa7+ Kxa7 29.Rxc8 Nxe5 30.c5 Qd7 31.Rcb8 Nc6 32.R8b5 g5 33.h3 h5 34.a4 g4 35.h4 Qf5 36.c4 Qe4 37.Rb6 g3 38.fxg3 Qe3+ 39.Kh1 Qxc5 40.Rb7+

0.00/44    9.d4 Nxc2+ 10.Kd1 Nxd4 11.Bxd5+ Kd7 12.Qg3 Qf6 13.Bg5 Qf5 14.Be4 Qe6 15.Bd5 Qf5

-0.37/44    9.Qe4 c6 10.a3 Na6 11.f4 Nac7 12.fxe5 Kf7 13.0-0+ Kg8 14.d4 Be6 15.Ne2 g6 16.Bd3 Bg7 17.c4 Ne7 18.Bg5 Qd7 19.Rad1 Re8 20.Rf2 Nf5 21.b3 h6 22.Bd2 Rd8 23.Nf4 Qxd4 24.Qxd4 Rxd4 25.Bc3 Rxf4 26.Rxf4 h5 27.Rf3 Kh7 28.h3 h4 29.Bxf5 gxf5 30.Kf2 Kg6 31.g3 hxg3+ 32.Rxg3+ Kf7 33.Rf3 Bh6 34.Bb4 Bg5 35.Bd6 Ne8 36.Rg1 Rg8

-0.58/44    9.a3 Nxc2+ 10.Kd1 Nxa1 11.Nxd5 Qh4 12.Nb6+ Ke7 13.Nxc8+ Rxc8 14.d3 Kd8 15.g3 Qf6 16.Qxb7 Bd6 17.Be3 Kd7 18.Qe4 Rb8 19.Qg4+ Ke8 20.b4 a5 21.Kd2 Qg6 22.Qxg6+ hxg6 23.Rxa1 axb4 24.a4 Kd7 25.h4 b3 26.Rb1 b2 27.Kc2 Ba3 28.Rd1 Rb4 29.a5 Kc6 30.a6 Ra4 31.Rb1 Rb8 32.Ba7 Ra8 33.Be3 R8xa6 34.Bxa6 Rxa6 35.f4 exf4 36.Bxf4 Kd5 37.Bd2 Re6 38.Bc3 Bd6 39.Bxb2 Bxg3 40.Bxg7

 Section C: 8...Nd4

C1 [+1.04]  d=24 9.Bxd5+ Kd7 10.Qh3+ Kd6 11.Qg3 c6 12.Bb3 Qe8 13.0-0 Nf5 14.Qd3+ Kc7

C2 [+0.83]  d=24 9.Qxd5+ Qxd5 10.Bxd5+ Kd6 11.Be4 g6 12.b3 Bf5 13.Bb2 c6 14.0-0-0 Rd8

Conclusion:

The section B mainline, which is best play for black, needs further work to determine the soundness of this line.