Edit. I gotcha. I read it wrong, b/c the poster typed it wrong. You're correct that it should be 3-6-1.
If it were 3rd to 1st to P, it would be 5-3-1. 6 is shortstop.
As a former pitcher, this is much more difficult than it looks. You gotta bust arse to get over there, stop, find the bag with your foot, while stretching for the ball. It's an underapreciated skill .... and sucks when you leave too much of your foot on the bag, and a jagoff runner takes it out on your ankle (spikes ya).