In the above line, more ambitious is 8...exd4 9.Nxd4 0-0!?, as in a match game between Siegbert Tarrasch and Emanuel Lasker in 1916, which led to a Black win in 23 moves. Another try is 5.0-0!? transposing to a variation of the Boden–Kieseritzky Gambit. 4.g3 Igor Glek has favoured 4.g3, preparing development of the bishop to g2. According to Pinski, Black's main responses are 4...Bc5 and 4...d5, both of which are reckoned to equalize for Black. A Halloween Gambit style 4...Nxe4 has also been tried at the grandmaster level as in two games between Ilya Smirin and Bartłomiej Macieja. 4.Be2 Though rarely seen, this move is playable. For example, if Black plays 4...Bb4, White has the responses 5.Nd5, 5.0-0, and 5.d3, which retain equality with accurate play. 4.a3 The quiet 4.a3, the Gunsberg Variation, is a specialty of Polish grandmaster Paweł Blehm. 4.Nxe5 A dubious gambit is 4.Nxe5?!, the so-called Halloween Gambit. After 4...Nxe5 5.d4, White tries to seize the centre with his pawns and drive the black knights back to their home squares. Grandmaster Larry Kaufman says that this line is refuted by 5...Nc6 6.d5 Bb4! 7.dxc6 Nxe4 8.Qd4 Qe7, which he attributes to Jan Pinski. According to Max Euwe's opening series volume 11, Black has a decisive advantage after 5...Ng6 6.e5 Ng8 7.Bc4 d5 8.Bxd5 c6. See also Italian Game Ruy Lopez Scotch game Three Knights Game Two Knights Defense References Bibliography Further reading External links Tim Krabbé's article on the Halloween Gambit Unorthodox Openings Newsletter #13, Critical Lines in the Halloween Gambit by Paul Keiser Chess openings