1.Nd1!
1.Rxb4+ loses to axb4 2.Nd1 b3 3.axb3 Kb4 4.Nc3 Kxb3
1...	Rxa4
2.Nc3+	Kb4
3.Kd4
The Black R is now trapped and White has limited the mobility of the Black pawns. Two variations are now possible:
[A]
3...	d6
4.Nxa4	Kxa4
5.Kc4	b5+
6.Kc3	b4+
7.Kc4	b3
8.axb3#
[B]
3...	b5
4.Ne4!	d6
5.Nc5	dxc5
6.Kd3	c4+
7.Kd4	c3
8.dxc3#
Kasparyan (1929)