Frank Marshall writes that this is "Stronger than 4.Qxd4 Nc6 5.Qe3 Bb4+! for then Black obtains a quick development. Nor is 4.e5 d5 5.Bb3 any better for White." The move initiates the Urusov Gambit, when Black can play 4....Nxe4 5.Qxd4 Nf6 6.Nc3 Nc6 7.Qh4 Be7 8.Bg5 followed by 9.O-O-O when White has good play for his pawn due to his excellent development. Black chooses to transpose to the Two Knight's Defense instead.
This move, which initiates the Perreux Variation of the Two Knights Defense, was very popular in the Dimock Theme Tournament. The main alternatives are 5.O-O and 5.e5. After 5.O-O Black can play into the main line of the tactically wild Max Lange Attack with 5....Bc5 6.e5 d5 7.exf6 dxc4 8.Re1+ or pursue the "Anti-Max Lange" with 5....Nxe4 6.Re1 d5 7.Bxd5 Qxd5 8.Nc3 Qa5 9.Nxe4 Be6. The move 5.e5 is often called the Modern Variation since it did not gain wide popularity until the mid-20th Century. It generally leads to a more positional struggle after 5.e5 d5 (Black can also try 5....Ne4 or 5....Ng4) 6.Bb5 Ne4 7.Nxd4 Bd7 8.Bxc6 bxc6. All of these lines have been fairly well analyzed and appear to lead to approximately equal play with chances for both sides.
If Black wishes to play into the main line of the Perreux Variation he should probably play the more straightforward 5....d5 6.exd5 Na5 when White has no good alternative to 7.Qxd4, with the position reached in the game. The text move allows White the trappy 6.Bb3 h6 7.f4 hxg5 8.fxe5 Nxe4 when best is probably 9.Qxd4 or 9.Bd5!? with complex play. Black's best, though, is to avoid the main line with 5....d5 6.exd5 Qe7+! when White practically has to play 7.Kf1. The resulting positions are generally equal, but Black has good play due to White's misplaced King. For more detailed analysis, visit the Perreux Variation of the Two Knights Defense web site.
As Marshall notes, White could not exchange Queens with 9.Qxd5 Nxd5 since "Black is for choice, inasmuch as he has two Bishops and his Knight is better posted." The Queen check is the only way for White to pursue an advantage. After 9....Be6, Black will end up with a weakened pawn structure, though at least he will be able to castle quickly and remove his King from the center of the board. The alternative way of blocking White's check, 9....Be7, is much less comfortable since the Black King will have to remain in the center to defend the Bishop, presenting White with pleasant attacking chances along the open central files. Marshall always prefers speedy development....
White has emerged from the opening with a slightly advantageous ending, since Black's isolated pawn at e6 is the only weakness on the board. Marshall writes that 12....Qxe6 is "better than 12....fxe6, as White's position is stronger with the Queens on the board." One wonders why, then, Marshall tried 12....fxe6 in his game with Santasiere, which he also won. Perhaps the Santasiere game was contested earlier?
It may seem logical to directly attack Black's weak pawn at e6, but this is a clear mistake since it allows Black to create a useful pin. Best is 14.Bg5! with a slight edge for White. Now Black is able to damage White's Queenside pawns, a fact which determines the outcome of the game.
Suddenly Black's weakling has asserted itself, helping Black to claim central space and cramp White's Bishop. White has lost all claim to the initiative and now must go on the defensive.
Since the key to winning a Rook ending is to play actively, Black's Rook cannot sit passively behind his isolated e-pawn to defend it. Instead, he must attack, exploiting the Queenside pawns he weakened at move 15. As C. S. Howell wrote of this position, "In the ensuing Rook and Pawn ending Black wins because he has the start." Or as Marshall writes, "A simple end-game wherein, in the exchanges that follow, Black is always slightly ahead." Marshall could have carefully counted out the remainder, but he may have simply recognized the winning line by instinct alone, knowing only that he would be slightly ahead throughout.
This loses instantly, but White was lost in any event. If instead 31.Ra5 a2! 32.Kc1 (otherwise Black wins the White Rook with 32....a1=Q+ 33.Rxa1 Rf1+ or simply 32....Rf1+ followed by Queening) 32....Kd7 and wins because White can do nothing constructive with his pieces. As C. S. Howell writes, "The White Rook must stay on the a-file while the Black King crosses to the Kingside and gets the pawns, then returning to force the win on the Queenside."
No doubt White had calculated 31....a2 32.Ra5 with the position described in the note above. But Black checks first while the Pawn is at a3 and thus prevents White's King from going to the b2 square. Nothing can be done to stop Black from Queening after 32.Kc2 a2, so White gives up.
The game demonstrates Marshall's superior technique in his first recorded meeting with the young Torre. But Marshall would never win another game from the rising star.
Some notes based on those of Frank James Marshall and C. S. Howell (American Chess Bulletin 1924, pages 194-195)