[Retros] Retros Digest, Vol 146, Issue 2

[Francois Labelle]

Nicolas Dupont wrote:
> Is it possible to construct a purely orthogonal mate without any 
> capture, ie some NC#(a,0,0)?

There's no example in 6.0 moves or less in my files. The best I have is 
with one capture:

1. h4 a5 2. Rh3 Ra6 3. Rd3 Re6 4. Rxd7 c6 5. Rc7 Qd3 6. f4 Qg3#
[and 5 more variants]

By the way, in your question I think you should specify that you're 
asking for a sound PG because taken out of context you're literally only 
asking for a mate and then one can answer

1. d4 f6 2. Qd3 h6 3. Qg3 Rh7 4. Qg6#

     François