Imagine the sheer frustration of nailing what seems like a perfect putt on the final hole, only for the ball to kiss the edge and heartbreakingly spit back out – that's the infamous 'lip out' in golf, a moment that can shatter dreams and leave players cursing their luck.
This frustrating twist isn't just bad luck; it's rooted in some fascinating physics, as uncovered by a recent study from the University of Bristol. For golfers of all levels, from weekend warriors to tour pros, the lip out happens when the ball strikes the hole's rim but refuses to drop, instead rolling away mockingly across the green.
Leading the charge is Emeritus Professor John Hogan from the University of Bristol's School of Engineering, Mathematics, and Technology. Drawing on his expertise in mechanics – the science of how objects move under forces – Hogan dove deep into this pesky phenomenon. His findings, detailed in the journal Royal Society Open Science, reveal the intricate dynamics at play.
Hogan even has a dramatic nickname for these treacherous balls: 'the golf balls of death,' evoking the dizzying stunt where daredevil motorcyclists ride vertically on a cylindrical 'wall of death.' It's a vivid way to capture how these putts can feel like a high-stakes gamble.
"We approached the problem through the lens of mechanics," Hogan explains. His analysis identifies two main categories of lip outs: the 'rim lip out,' where the ball's center of mass never dips below the green's surface, and the 'hole lip out,' where it briefly does. For beginners, think of the center of mass as the ball's balance point – if it stays high, the ball teeters without committing to fall in.
Central to both scenarios is what Hogan calls a 'family of degenerate saddle equilibria' along the hole's rim. In simple terms, this is like a precarious tipping point: the ball is balanced unstably on the edge, neither fully inside the hole nor safely back on the green. It's that nail-biting moment where the slightest nudge decides its fate.
In a rim lip out, the ball circles the top of the hole at a steady angle and speed, almost like it's orbiting the rim. But introduce a tiny disturbance – say, a speck of dirt, a gentle breeze, or uneven spin from the putt – and it could either plop in for glory or bounce back out. And this is the part most people miss: even pros can't always control those micro-factors, turning precision into a game of chance.
The hole lip out, on the other hand, is rarer and happens under very specific conditions. Here, the ball actually enters the hole and swings around its inner wall in a pendulum-like fashion, much like a kid on a swing gaining momentum. As it does, its potential energy – the stored energy from its height, similar to water held back by a dam – transforms into rotational spin. If the ball avoids hitting the hole's bottom, this spin can propel it back up to the rim and out onto the green again. Picture it as the ball gaining just enough whirl to escape its temporary trap, adding an extra layer of unpredictability to the shot.
But here's where it gets controversial: some golfers swear by feel and instinct over cold science, questioning if dissecting the physics really helps on the course. So, how can you tweak your approach to dodge these disasters? It's not straightforward, but Hogan offers practical wisdom.
"My buddies on the fairway often blame lip outs on hitting too aggressively," Hogan notes. Yet his research suggests aiming dead center and arriving at the rim with minimal speed is key. That delicate momentum provides just enough push to nudge the ball over the edge into the hole, without the excess to sling it around and out. For example, visualize a slow-rolling marble gently toppling into a cup versus one zipping past – it's all about that Goldilocks balance of 'just right.'
Hogan's insights stem from the broader field of mechanics, pioneered by Sir Isaac Newton with his famous Laws of Motion. Originally used to chart planetary paths, these principles now illuminate sports, helping us understand everything from a curveball's arc to a sprinter's stride.
This golf study extends Hogan's earlier explorations into sports physics, including the ollie trick in skateboarding and the rebound paths of basketballs off the rim. Each project shows how timeless scientific tools can demystify athletic feats, making the impossible seem a bit more achievable.
For more details, check out the paper: 'Mechanics of the golf lip out,' published in Royal Society Open Science (2025), DOI: 10.1098/rsos.250907, available at royalsocietypublishing.org/doi/10.1098/rsos.250907.
Citation: Golf's cruelest moment: The physics behind the 'lip out' phenomenon (2025, November 4), retrieved 4 November 2025 from https://phys.org/news/2025-11-golf-cruelest-moment-physics-lip.html.
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What do you think – does knowing the physics behind lip outs give you an edge, or is golf's magic in its mystery? Have you suffered a game-changing lip out, and would this advice change how you putt? Drop your stories and opinions in the comments; I'd love to hear if science sways you or if it's all about that gut feel!
