This pawn advance marks the Modern Variation of the Two Knights Defense, which began to gain attention after World War I. It did not become the most popular line of play until the 1950s when it was adopted by Mikhail Tal. This may be the strongest move for White, and I hope to provide more coverage of it here at some time in the future. For now, I have focused my attention on the Perreux Variation for a number of reasons: (1) it was the most popular line in the Dimock tournament, (2) the games from the Dimock event add considerably to the theory of the Perreux Variation and therefore integrate well with that analysis, (3) the Perreux line is not covered much in today's books on the opening, (4) there are many fewer sidelines in the Perreux variation and the theory is not too onerous for me or for my readers, and (5) because the Perreux Variation is much easier to understand than the Modern Variation and will therefore appeal to the general audience I am trying to reach with this website.
Though this is the most common response, both 5....Ng4 and 5....Ne4 are playable. The move 5....Ng4, which puts pressure on the pawn at e5, is especially tough to crack, and best might be 6.Qe2 Qe7 7.Bf4 d6 (7....f6!? is also played) 8.exd6 Qxe2+ 9.Bxd2 Bxd6 10.Bxd6 cxd6 11.Na3 when White will have a slight edge in the ending once he recovers his pawn. The main line with 5....d5 leads to interesting middlegame positions where White has clearer strategic goals in trying to control the dark squares and to use his kingside pawn majority to open lines for attack.
In his notes on this game in the American Chess Bulletin of 1924, the commentator C. S. Howell calls this a "flashy move," and says that "more correct is 7....Bd7, and if 8.Nb3 not 8....Be6 as given in the 'books,'" but either 8....Nb4! or 8....Qh4!? Play after the safer 8....Nb4 might go 9.Be2 a5 10.a3 a4! 11.N3d2 Nc6 12.Nf3 Be6 13.O-O Bc5 and Black stands quite well. Meanwhile, an interesting struggle ensued following 8....Qh4 in Tartakower-Reti, Baden Baden 1914: 9.O-O O-O-O 10.Bxc6 (a cute miniature occurred in Boeven-Jense, Corr. 1972: 10f4?! Nxe5! 11.Bxd7+ Nxd7 12.Qxd5 Ndf6 13.Qf5+ Kb8 14.g3?! Qh6 15.Kg2? Rd5! 0-1) 10....Bxc6 11.Nc3 f6 12.Nxe4 dxe4 13.Qe2 Rd5 14.e6 Bd6 15.h3 Re8 16.c4 Rd3 17.Be3 f5 18.c5 Be5 19.f4 Bf6 20.Na5 Rxe6 21.Nxc6 Rxc6 22.Rad1 Rd8 (Black's pieces have gotten completely uncoordinated) 23.b4 Re6 24.Qc4 Ree8 25.c6! Be7 26.Qb5 1-0.
C. S. Howell calls this "the correct reply." Less good is 8.O-O when Black can continue his gambit with 8....O-O!? with a strong initiative if White accepts by either 9.Nxc6? bxc6 10.Bxc6 Ba6! 11.Bxa8 Bxf1 as first played in Dufresne-Anderssen, Rotterdam 1861 (!) or 9.Bxc6 bxc6 10.Nxc6?! Qh4! 11.Be3 Ba6!
Howell writes: "An unexpected move. Black is looking toward the ending and hopes to emerge with four pawns to three on the queenside, while his two hold three on the kingside." If White captures the Knight, he will have to return the piece at some point since his Knight at d4 is pinned and cannot escape the attack after 13.fxg5 fxg5. Torre likely thought his chances were good after the exchange of pieces due to his faster development and the possibility that Black's King would become exposed. In any event, White practically must capture since his pawn at e5 is under too much pressure to decline the invitation.
A little more forcing is 14.c3, threatening to retreat with Nc2 and forcing 14....exd4 15.Bxd4 with good attacking chances for White, who threatens both Re1 and b4. But Torre rightly prefers to complete his development, and he plans to use the Knight to secure control of the c5 square.
Howell writes: "Mr. Bigelow is probably right in his contention that he should have delayed the capture and played 14....O-O-O, which is not so bad as it looks" (with his fortress pawns so disrupted). Gabriel Velasco gives the line 14....O-O-O! 15.Qd3 exd4 16.Bxd4 Bxd4 17.Qxd4 Kb8 "with a roughly equal position." As the sequel shows, Black needed to get his King to safety.
Howell writes: "Making a place for his King, but losing time. 15....O-O-O was a lesser evil." Black must block White from exploiting the alignment of his King and Queen along the e-file, so castling was probably in order. After 15....O-O-O, White gets his attack rolling by 16.Na4! but Black certainly has resources following 16....Bb6.
Black imagines that his King will be safe at d7, protected by his little fortress of center pawns. But Kings are rarely safe in the center of the board where all of the opponent's pieces can converge in the attack. Torre now plans on opening up the center and securing control of the c5 square by Na4 and c4, but this requires some preparation.
The Queen serves multiple functions on this square - overprotecting the c5 square, helping to put pressure along the e-file, protecting the pawn at g5 (though Black has so far not had time to take it), and creating a battery with Queen and Bishop that can win the a-pawn at any time. After 19.Rae1, White's pieces will all have commanding positions - but especially his Bishop at d4, which puts pressure on all parts of the board.
Offering an exchange of Queens to ease the pressure, but White is enjoying his attack too much. White's position is so strong, though, that he actually keeps the advantage after 20.Qxe7+?! Rxe7 (20....Bxe7 21.Rf7) 21.Rxe7+ Bxe7 22.Rf7!
One sign of Black's helplessness is that he has nothing better than this sad retreat.
The beginning of the end as now the position will be blown open. White now threatens to trap the Bishop in the center of the board with 22.c5, prompting Black's response.
Better than 23.Nxc3 Rad8. The Knight has not yet completed his mission of dominating the c5 square. When he finally arrives at his destination, the game will be over.
A blunder or suicide perhaps, but the game was lost in any event. If 27....Kc8 28.Qg4+ is deadly.
28. Re6# 1-0