Is the 5 pin not the kingpin in 10 pin bowling?

Answer 1

The 5-pin, the central pin in a Bowling rack, is called the kingpin. One theory as to the origin of the name come from the related game of ninepins, in which one of the ways to score the most points was to knock down all of the pins except the center one.

It may help to think of the other pins as being the kingpin's court; they do their best to protect their liege from being bowled over by the enemy cannonball. Sometimes, they even succeed; at least on the first ball.

And the 5-pin isn't the only pin to have a special name. The 1-pin is called the headpin, for obvious reasons; and the 7- or 10-pin is often called a corner pin.