The process of drilling a hole in the bottom of a bowling ball and afterwards placing your penis on the inside of said hole. After this you make someone touch your penis when they put their fingers into the bowling ball's three holes.
Griffin: I gave Sarah a Minnesota Pincher last night at the bowling alley.
Griffin: When you place your dick in a bowling ball and make her touch it without her knowing.
Justin:How did that go for you?
Griffin:Great until she threw the ball with me inside it.
The bowling equivalent to the "Penis In The Popcorn Box" trick. It involves drilling a hole into the side of the bowling ball opposite the fingerholes so that when a person grips the ball properly (through the fingerholes) there is a slight chance his/her fingers will graze the penis inserted though the other side. If noticed by the grazer, he/she should immediately begin to mash the part of the penis touched between finger and bowling ball, effectively pinching the shit out of it.
"Baby, wait, wait, Wait, WAIT! ... My dick's in the ball..."
And that's why they call her the Minnesota Pincher.