[solution]
- In the actual game black played Qg6
- and then Rd5 and
- waited for white to run out of
- rook checks. This works, but
- I like the simplicity of Rd4+
- followed by Qf6+ winning the rook on move 3.
- The endgame tablebases say that there are a variety of mate in 6's, here. The easiest one to understand is maybe 1. ... Kf2. 2. Rb4 (Rc4 Rd5 mates faster) Kg1 3. Rb1+ Qxb1 4. Kg5 Rf2 with an easy mate on move 6.
