What is the largest recorded number of chess pieces involved in a checkmate move?

i was playing chess on the computer and i managed to perform checkmate using 6 pieces. whilst i doubt very much this is the most you can use, i can only ever remember achieving checkmate with 2, 3 or 4 pieces. ive tried looking to see if there are any records for the number of pieces used in a checkmate simply because i'm interested and I've never thought about it before...|||It cannot be 17 or more pieces to perform checkmate, because


white and black only get 16 chessmen each to begin with. We can


contrive a game and position in which the most (all 16 chessmen) are involved


in a checkmate move. Nobody much cared until computers appeared interested.|||i had to use 7 once


played against an amateur, had no rooks developed and gave my queen away to set up some competition


in the end used my king, 2 bishops, 1 knight and 3 pawns to give chekmate.


Blimey, hes good at evading|||actually, it takes 17 pieces cuz ive done it before


it takes 8 pieces to block the kings direction from moving


and then it takes another 8 to defend those pieces


then it takes one more knight to give checkmate|||Seeing how the king can only move to 8 possible spaces, the maximum number of pieces involved would be 8. I'm sure there is some way to do it.