Single Comment

'Priest a7-b6' is one solution. There is a second solution. That 'Priest a7-b6' is Check and Mate, because DoubleCannon then has the capturing route a8(-a7-(turn 45 degrees and jump)-c5-d4-e3-f2)-g1. To prove it, 'King g1-g2' runs into Canon. 'King -f2' has the same check by the same DoubleCannon. The only two White pieces that can reach DoubleCannon-a8's pathway, to block it, are Queen-e2 and Pawn-d3. 'Pawn d3-d4' blocks DoubleCannon, as that DoubleCannon would have to capture the Pawn along it. However, 'd3-d4' gives the other DoubleCannon *immediate* pathway c7(-c6-c5(turn 45 degrees and jump)-e3-f2)-g1, still Check. And 'Queen d3-d4' makes a pathway for Diagonal Narrow Crooked Nightrider at b5, NN b5(-d4-e2)-g1. So, that is clearly Checkmate, without DoubleCannon ever (permitted) capturing Queen. 'Priest a7-b6' is therefore one established Checkmate. Which of Rose, Crooked Nightrider, plural-path Dragon, DNCNN, Priest, DoubleBarrel, Canon or the other DoubleCannon enable by one different move a comparable Mate-in-One at once? What is the second solution?