Proof Game in 4.0 moves
a) diagram b) -Qd8
Solution to a):
1. d3
{Pretty obvious start}
1... e6 2. Qd2 Ba3
{!! Brilliant clearance move to allow the wQ to use the Bishop's diagonal}
3. Qb4 f6
{waiting}
4. Qf8+
{an ingenious choice of sacrifice square}
4... Bxf8
Solution to b):
1. d3 e6 2. Bh6
{there's that same brilliant clearance idea - except that white does it in this twin!}
2... Qg5 3. Qc1
{white finds a convenient way to dispose of his Q}
3... Qxc1+ 4. Bxc1
{Bishop switchback, just like twin a)!}
4... f6
Nice feature!