snooker

[superstarsmi]

what is the shot called when an object played ball hits three cushions and lands in the middle pocket

[TCL-MUMPING]

It's called a cocked hat as that has three corners

[R1Geezer]

As TCL says it is called a "Cocked Hat double", it is quite rare, usually an unintended shot. Even rarer is the lengh wise version ending in a corner pocket.