Bowling-Ball Pins Explained

A Quick Explanation of a Bowling Ball's Pin

An Undrilled Bowling Ball
The solid yellow dot is the pin. The other marking is the CG. Photo by Jef Goodger

Not to be confused with the pins at the end of the lane, every bowling ball is marked with a colored dot, which represents the ball's pin. The pin is vital in determining how to drill your ball to get your desired reaction on the lanes.

What is the Pin?

The pin marks the top of the core inside the bowling ball. It is also the point around which the ball wants to rotate. Given an infinite length and time, a ball will eventually rotate around the pin, either with the pin down on the lane or on top of the ball.

A 60-foot bowling lane is generally not long enough (assuming a shot of even moderate speed) for the ball to completely shift itself into rotating around the pin, but it's always trying to get there.

This is why the pin is so important in drilling balls. Knowing the ball always wants to rotate around that spot, you can have your ball drilled to make it work for you in any number of ways. Other factors, such as your positive axis placement (PAP) and track are also crucial in optimizing your drilling, as the relationship between the PAP and pin will directly impact where to put the holes in your ball.

How the Pin Got There

Bowling-ball manufacturers have to center the cores perfectly inside the ball and to do this, they have to suspend the core in a stationary position while the mold hardens. They use a small pin to support the core during this process.

After the mold hardens, the pin is removed, which leaves a small hole in the ball.

Typically, this is filled with a solid color that contrasts with the main color scheme of the ball, and that is the colored dot you see on the ball.

Within a couple inches of the pin is a smaller marking, usually a tiny punch or a small circle. This is the center of gravity and this generally doesn't affect the behavior of the ball (unless you're a highly advanced bowler), but is valuable, along with the pin, in helping a ball driller know where to put the holes in your ball.