Overview
- A peer-reviewed study by John Hogan of the University of Bristol and Mate Antali of Széchenyi István University is published in Royal Society Open Science.
- The analysis distinguishes a rim lip-out, where the ball’s center of mass stays above green level, from a hole lip-out, where the ball descends and can climb out if it avoids touching the bottom.
- Using a unified no-slip rolling model, the authors map boundaries by arrival speed and impact offset that separate immediate capture, rim ride, rim lip-out, or entry into the hole.
- High speeds and off-center approaches tend to produce rim lip-outs, whereas slower, more central lines favor capture unless spin inside the cup drives a rarer hole lip-out.
- Near these boundaries, tiny perturbations such as grain, wind, slight spin, or rim imperfections can flip outcomes, and the authors advise aiming close to the center with low arrival speed despite real-green variability.