# Fastest way to helpmate

What is the fastest way to checkmate/helpmate white(A helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating Black/White) in this given position? It is black to play.

Fen: 8/7p/8/8/2k5/6P1/7P/7K b - - 0 1

Bonus Question: Can you find the fastest way to checkmate white without promoting the black lone black pawn?

• The bonus question seems hard, I haven't found the final position yet. +1 May 24 at 2:32

Naive mate with promotion:

1...h5 2. Kg1 h4 3. Kf1 hxg3 4. Ke1 gxh2 5. Kd1 Kc3 6. Kc1 h1=Q# Final position: 8/8/8/8/8/2k5/8/2K4q w - - 0 7

• wow. nice job! 6 moves is the one to beat now
– JLee
May 24 at 1:51
• That probably is an optimal solution. I'll wait if someone finds a better one. May 24 at 12:07

Bonus Question: Black moves the pawn to

h3 and King to f2 while white pushes the g pawn and promotes to a queen or rook. Then white plays Qg2 (or Rg2) and black takes with the pawn for a 7-move checkmate.

• Nice job. This is the solution I intended. May 24 at 4:12
• Okay, took a second to figure out what was going on here because the board is reversed. Should change that 6 to 3 and the 7's to 2's. Especially since the board in the OP is explicitly labeled that way. May 24 at 15:42
• I got the essence of the solution, so I didn't really notice the notation were wrong. May 24 at 17:58