In Part 1 Silman gives the basic requirement as follows:
Bishop on the b1-h7 diagonal
Knight that can land on g5
Queen that can check on h5 or, in some instances, along the b1-h7 diagonal
Other factors that strengthen the attack are
Bishop on the c1-h6 diagonal
Rook that can join in on the attack and a pawn on e5. A pawn on e5 is a very important since it prevents the defensive …Nf6. A defending Queen on d8 or Bishop on e7 might prevent the attack since Ng5+ can be traded.
The initial Bishop sacrifice is often just a small tactic designed to win material, and has little to do with an actual mating attack.
In this game Black’s 13th move made the sacrifice perfectly sound although according to Houdini 2 the preliminary 14.Ng5 first would have strengthened the attack.
The opening was a gambit I sometimes play against the French that has served quite well. 3.Be3 is generally known as the Alapin-Diemer Gambit. Emil Diemer played 3.Be3 against the French Defense many times with some impressive wins. The gambit can be declined with 3...Nf6, but White gets a good game after 4.e5! The critical line is 3...dxe4. White can play 4.f3 or 4.Nc3, but the main line is 4.Nd2 Nf6 5.f3. Alapin's original idea was 5.c3 and 6.Qc2. With Diemer's continuation of 5.f3, the pawn on e4 is double attacked. More often than not, Black plays 5...exf3 6.Ngxf3. Apparently Black decided it was too risky to play against the gambit and chose to transpose into something he was, more than likely, familiar with. We reached a side line in the Advance Variation, Chessdorcom has a couple of nice articles on it, also: Part 1 Part 2