CONCEPT · BALL STRIKING INTERMEDIATE FOCUS
Gear effect is the spin an off-centre strike puts on the ball. Off the toe, a driver's head twists open, and its face rubs draw spin onto the ball; off the heel, fade spin. That's why a driver's face is curved: the curve starts the miss out, so the spin brings it back.
Skill split
01 · Overview
~2 min read
Gear effect is what happens when the ball meets the club away from the middle of its face. Hit it out towards the toe, and the ball pushes the toe back: the head twists open, around its centre of gravity. As it twists, the face rubs across the ball and spins it the other way, like two gears meshing. So a toe strike gets draw spin, and a heel strike gets fade spin, with the same path and the same face angle. Only where the ball met the club has changed.
It's strongest with a driver, because a driver's centre of gravity sits deep: about 25 to 50 mm (one to two inches) behind the face, TrackMan says. The deeper it sits, the more gear effect; the more the head resists twisting, the less. An iron's centre of gravity sits close behind its face, so its gear effect is far smaller. That's why an iron's face is flat, and a driver's is curved.
A driver's face curves from heel to toe, called bulge, and from top to bottom, called roll, so it points a different way wherever the ball meets it. TrackMan's figure: about 2° more open for every 10 mm towards the toe, and about 2° less loft for every 10 mm low. For a right-hander, a toe strike starts right of a centred one, and its draw spin curves it back towards the middle; a heel strike starts left, and its fade spin brings it back. The curve reduces the miss. It doesn't cancel it, and off the toe or the heel the ball leaves the face slower, so it doesn't go as far. A physicist who analysed the curved face found it makes a drive likelier to finish mid-fairway than a flat face would. No rule sets the curve, and makers differ: in patents, its radius runs from roughly 10 to 17 inches.
Up and down the face, roll and gear effect work the same way. Strike it high, and the ball launches higher, with less spin. Strike it low, and it launches lower, with more: up to about 1,000 rpm more, TrackMan says. In one robot test at 95 mph, averaged over 25 drivers, a centred strike went 222 yards at 11.4° and 2,710 rpm, and one low on the heel went 203 yards at about 9° and 3,310 rpm. That's a robot test, not what every golfer loses. The spin a centred drive gets is a matter of spin loft.
So where do golfers really hit it? Patents that mapped golfers' strikes find them clustered near the middle and thinning out towards the edges, along a slanted oval from high toe to low heel. The typical miss, one equipment writer says, is high on the toe; heel misses are rarer, and usually low. And in a study of 285 golfers, lower handicaps varied less in where they struck it.
To find your own pattern, spray foot powder on the face, hit a few drives, and read the marks. Standing too far away and reaching is a common cause of toe strikes; another is the arms pulling in through impact. So for marks towards the toe, one teacher's advice is to stand a little closer, and for marks towards the heel, a little further away. Marks high or low are worth checking against your tee height. Then guard the side you stray to: for toe marks, lay a head cover just inside the ball and swing without touching it; for heel marks, lay it just beyond the ball, as in the head cover drill. To train the club to arrive at the right distance from you, lay an alignment stick beside the ball, along the target line, and make small, slow swings across it: from the far side to yours for heel marks, from yours to the far side for toe marks. More strike drills.
4 components that build the move
01 · THE STRIKE
The ball meets the face away from its sweet spot: out towards the toe, in towards the heel, or high or low. Path and face can be the same as a centred strike; only the contact has moved.
02 · THE TWIST
The ball pushes that side of the head back, and the head turns around its centre of gravity: open off the toe, closed off the heel. The deeper the centre of gravity, the bigger the effect, which is why it's strongest with a driver.
03 · THE GEARS
As the head turns, the face rubs across the ball and spins it the other way, like two gears meshing: draw spin off the toe, fade spin off the heel. Low on the face, more backspin; high, less.
04 · THE CURVE
A driver's face curves, so it points a different way wherever the ball meets it. A toe strike starts right of a centred one and its spin curves it back; a heel strike starts left. The curve reduces the miss. It doesn't cancel it.
02 · The Reference
3 of 18 · hand-selected
Editor's Pick · #1 · 7:26
One delivery, three outcomes: with the same path and face, a straight drive, a slice or a hook, purely from where the ball met the face. Then foot spray on a real drive shows why it curved.
ChrisRyanGolf · beginner
Editor's Pick · 16:39
A launch monitor reading that should be a pull-hook: the face left of a path that was already left. The ball faded, because it came off the heel, and the coach names it gear effect.
Meandmygolf · advanced
Editor's Pick · 13:08
Foot spray and a launch monitor on three drives: the strike low on the face spun the most and carried the shortest. He points out that the attack angle changed too.
Top Speed Golf - Clay Ballard · intermediate
04 · The Experts
3 perspectives · same drill
ChrisRyanGolf · One delivery, three strikes
Why it works
With the same path and face, a heel strike starts left and curves right, a toe strike starts right and curves left, and the middle goes straight. Where the ball meets the face decides the curve.
“what we have with the driver is what we call gear effect which is is how the golf club twists relative to where the golf ball is hitting on the club face
Elite Performance Golf Studios · Read the strike before the swing
Why it works
Off the toe the face kicks open, so the ball starts right, and the draw spin from gear effect curves it back. A delivery that would fade from the middle can come out looking like a draw.
“because if you toe it, kicks the face open, ball starts right, gears back to the left. So, it looks like he's hitting a functional draw, even though the delivery slightly out to in, face slightly open.
Danny Maude · Guess, then read the spray
Why it works
Feel can mislead: his golfer felt the heel and was moving closer to the ball to fix it, but the spray mark was on the toe. Guess first, then read the mark.
“I need you to get really good at noticing where that club is striking on the face because if you don't know where it's striking on the face, how can you ever adjust to it?
04 · Practice it
1 drill
Drill
Practice protocol with timestamped demonstrations across 6 videos.
05 · FAQ
Answered from the library
Gear effect is the spin an off-centre strike puts on the ball. Hit it towards the toe, and the ball pushes the toe back, so the head twists open around its centre of gravity. As it twists, the face rubs across the ball and spins it the other way, like two gears meshing. A toe strike gets draw spin and a heel strike gets fade spin, with the same path and face angle.
Not on a driver, as a rule. Gear effect puts draw spin on a toe strike and fade spin on a heel strike, but the face is curved, so for a right-hander a toe strike starts right of a centred one and a heel strike starts left. The spin then curves each back towards the middle. On a flat face, which no one has measured on a driver, the ball would start near the line and the spin would carry it away.
Because of gear effect. A driver's centre of gravity sits about 25 to 50 mm (one to two inches) behind the face, TrackMan says, and the deeper it sits, the more gear effect. The curve starts an off-centre strike out so its spin brings it back. An iron's centre of gravity sits close behind its face, so its gear effect is far smaller, and its face is flat.
Bulge is the curve of a driver's face from heel to toe; roll is its curve from top to bottom. Together they make the face point a different way wherever the ball meets it: in TrackMan's figure, about 2° more open for every 10 mm towards the toe, and about 2° less loft for every 10 mm low. No rule sets the curve, and makers differ: in patents its radius runs from roughly 10 to 17 inches.
Yes. Strike it high, and the ball launches higher with less spin; strike it low, and it launches lower with more, up to about 1,000 rpm more, TrackMan says (it gives no figure for high strikes). In one robot test at 95 mph, averaged over 25 drivers, a strike low on the heel launched at about 9° with 3,310 rpm and went 203 yards, against 11.4°, 2,710 rpm and 222 yards from the middle.
Around the middle. Patents that mapped golfers' strikes find them clustered near the centre and thinning out towards the edges, along a slanted oval from high toe to low heel. The typical miss, one equipment writer says, is high on the toe; heel misses are rarer, and usually low. In a study of 285 golfers, lower handicaps varied less in where they struck it.
Spray foot powder on the face, hit a few drives, and read the marks. A ball leaves a print about 18 mm (0.7 in) across. Don't use smash factor as the test: TrackMan warns it isn't a measure of a centred strike.
Check your setup first. Standing too far away and reaching is a common cause of toe strikes, so one teacher's advice is to stand a little closer for toe marks and a little further away for heel marks. Then guard the side you stray to: a head cover just inside the ball for toe marks, just beyond it for heel marks, and swing without touching it.
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06 · The Library
YouTube-indexed · expert-graded
Video · 6:50
Golf Studio
Video · 7:26
ChrisRyanGolf
Video · 16:39
Meandmygolf
Video · 13:08
Top Speed Golf - Clay Ballard
Video · 33:31
Elite Performance Golf Studios
Video · 19:39
Fraser Golf Institute
Video · 12:20
Swing Quest Golf
Video · 21:24
Fraser Golf Institute
Video · 8:50
Athletic Motion Golf
Video · 13:02
AlexElliottGolf
Video · 5:47
Your guide to better golf - Marcus Edblad PGA Pro
Video · 10:11
Effortless Senior Golf
Video · 15:57
Danny Maude
Video · 25:47
Meandmygolf
Video · 2:49
Top Speed Golf - Clay Ballard
Video · 2:15
Dan McCracken Golf
Video · 40:21
Fraser Golf Institute
Video · 11:31
Good Golf Coaching
Spray foot powder on the face, hit a few drives and read the marks. Then guard the side you stray to: a head cover just inside the ball for toe marks, just beyond it for heel marks.