DeVaney Bowling View Schedule

Free Interactive Bowling Tools

Rule of 31 & Spare Math Calculator

Calculate your target breakpoint board and 3-6-9 spare feet adjustments instantaneously.

1. The Rule of 31 Breakpoint Calculator

The Rule of 31 is the classic PBA Tour formula for finding your target exit board at the end of the oil pattern. Subtract 31 from the total oil pattern length in feet to determine your ideal exit board.

Target Breakpoint: Board 9 (at 40 feet)

2. The 3-6-9 Spare Adjustment Calculator

Select the pin target to calculate your foot shift relative to your strike stance while keeping your eye target over the center arrow.

Move feet 9 boards LEFT. Cross center arrow with plastic spare ball.

Want 1-on-1 Guidance on Your Game?

Book a private lesson at Strike Force Lanes in Greenfield, IN or send video for remote coaching.

Text Mike (702) 701-1494