PEORIA (AP) – With the exactitude of a brain surgeon, Tim Pallai prepares to sink a whirring drill bit into a new bowling ball.

For Pallai, this is serious business, a mix of three-dimensional mathematics, physics laws and bowling theory. But he’s creating no mere house ball that some little kid will fling between his legs and bounce into a gutter. Pallai crafts bowling balls as personal as the fingers that will go into it.

By wild estimate, counting each drilled digit, he has done this perhaps a quarter of a million times.