H. G. Muller wrote on Thu, May 28, 2020 06:49 PM UTC:
Why does it say stalemate is not possible? It seems the diagram of which it is claimed the best Valkyrie move is capturing the Forest Ox (Vf1xf7) actually leads directly into stalemate, through that move. After it black has no legal moves, and after hypothetical null move white cannot capture both his Kings at once, so he is not in check either. (And besides, the last black piece could have been taken elsewhere, so that neither black King would have been under attack.)
Why does it say stalemate is not possible? It seems the diagram of which it is claimed the best Valkyrie move is capturing the Forest Ox (Vf1xf7) actually leads directly into stalemate, through that move. After it black has no legal moves, and after hypothetical null move white cannot capture both his Kings at once, so he is not in check either. (And besides, the last black piece could have been taken elsewhere, so that neither black King would have been under attack.)