Wilkes-Barre Variation (5.Nxf7)
Oct 19, 2009, 7:10 AM 4
White accepts sacrifice, 6.Kxf2
Main ideas: Black plays Nxe4+ and frees the queen. Black tries to capture the bishop with check to gain a tempo and capture the knight, eliminating the threat of the rook capture. Black can also aim for forks on the weak c2 and possibly f2 squares. Black may also be able to move the h8 rook out of danger if he has a tempo after the queen is clear, but it slows Black's attack. It seems a viable option though.
White declines sacrifice, 6.Kf1
Seems difficult for Black to force a win. Some lines end in advantage for White and must be carefully avoided, and Black often has to play for a draw by perpetual check. Even one line which forces the white king out into the open on the queenside seems to eventually let the king escape with a huge material advantage for white.
White declines sacrifice, 6.Ke2
After playing 6. ...Nd4+ this simply transposes into the previous two lines with an extra tempo for black if white plays Ke1 or Kxf2. Have yet to analyze what happens if the king advances instead.