Twin

a)

1.f4!

[thematic try 1.e4? Rxe4!–+ (1...Rxf8? 2.Kg7 f5 3.f4!=); 1.Kg7? f5! 2.Bd6 (2.f4 Kxe2–+) 2...Re6!–+]

1...Rxf8

[1...Kxe2 2.f5! Rxf8 3.Kg7=; 1...Re6+ 2.Kg7! f5 3.e4! (3.Kf7? Rc6!-+) 3...fxe4 4.f5=]

2.Kg7 f5! 3.e4!!

[3.Kxf8? Kxe2–+]

3...fxe4 4.Kxf8 e3 5.f5 e2 6.f6 e1Q 7.f7=

 

 

b)

1.e4!

[thematic try 1.f4? Rb6+! 2.Kg7 (2.Kg5 Kxe2–+) 2...f5! 3.e3 (3.e4? fxe4–+) 3...Tb5! 4.Kf6 Ke2 5.Bd6 Kxe3 6.Be5 Ke4–+; 1.Kg7? f5! 2.Bd6 Rb6! 3.Bg3 Kxe2]

1...Rxf8

[1...f5 2.exf5= (2.Bd6) ]

2.Kg7 f5!

[2...Re8 3.f3 Re7 4.Kf6=]

3.f4!!

[3.f3? fxe4 4.fxe4 Re8–+; 3.Kxf8? fxe4–+]

see a) =