Discoveries (theoretical novelties) in c57 Fritz variation (two knights defence), changing appraisal of its very important systems, are present in this investigation.

Summary of analysis (author's novelties are marked by symbol "AN")

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.ed Nd4

Paragraph 1: 6.d6 Qd6 7.Bf7 Ke7 8.Bb3 Nb3 9.ab h6 10.Nf3 e4 11.Nh4 Kf7

The move 11.Nh4 was realized only once (McGiffert-Carpenter, 1984), and its strength wasn’t understood. The move 11...Kf7!? is not only move, but after it white can’t save its knight on h4 from g7-g5. Thus, black wins after 12.g3?? g5 13.Ng2 Bg4 (McGiffert-Carpenter, 1984).

12.f3!!AN (White stands slightly better.) That is why 11.Nh4! is a new strong and important gambit. [Addition by Bruno Berenguer: I suggest to call this new gambit with a sacrifice of a knight (11.Nh4) as “Nh4-Bukayev gambit” in honour of its author! He agrees to this gambit’s name.]

Its acceptance is a combination of 11...Kf7 with further (immediately or after previous preparation) ...g7-g5 and ...g5xh4. It should be noted, that black wins after 12.0-0?AN g5 13.f3 e3!

I

12...g5 (12...e3 13.g4. White stands slightly better.) 13.fe Qf4! (13...Bg4 14.Nf3; 13...gh 14.0-0 with the idea d4! or 14.d4! Ne4 15.0-0 with the idea 16.Bf4, 17.Be5) 14.Nf3. White stands slightly better.

II

12...Qe6 13.f4

or 13.Qe2 g5 (13...e3 14.f4 or 14.g3) 14.fe gh 15.e5

With advantage in both cases. It should be noted, that black wins after 13.0-0? e3!

III

12...Qe7 13.Qe2! (13.0-0? e3!) 13...g5 (13...e3 14.f4 or 14.g3.) 14.fe gh 15.e5. White stands better.

IV

12...Qe5 13.Qe2 (The move 13.0-0!? is possible too.) 13...g5 14.d4 Qd4 15.Ra4 with a strong attack. White stands better.

Auteur : Y.Bukayev