Second key · Deftly Shaking the War Bell (what the solver found)

What the solver found: an exact audit of the classical manuals

11 moves

Deftly Shaking the War Bell (妙振兵铃) — Elegant Pastime Manual (適情雅趣, 1570), no. 15 The book opens Rh10+ and mates in 6. So does Pd10+: the key is not unique. The mainline is the book’s solution; a branch, where there is one, is what the solver found. Record from dpxq.com.

Pd10+ forces mate in the same 6 moves as the book’s Rh10+. A composition is asked for one solution, so a second key is a fault.