Glossary

The clubhouse bar — golf's affectionate name for the unofficial stop that follows the eighteenth green.

The umbrella term in Rule 16.1 for four course features that always carry free relief: animal holes, ground under repair, immovable obstructions, and temporary water. Ground under repair covers mainte

A hole-in-one: the ball goes from the tee into the cup with a single stroke. Aces almost always happen on par-3s, where the green is reachable in one, and they're a genuine lightning strike — the odds

The positions on a modern driver's or fairway wood's adapter sleeve that let you change loft, lie, and effective face angle with a torque wrench instead of a new club.

The maintenance practice of punching holes in the turf to relieve compaction, manage thatch, and let roots breathe — the reason your favorite green looks freckled a couple of times a year.

Free relief from the punched holes left behind when a course aerates — but only when the Committee switches it on with Model Local Rule E-4, because the standard Rules treat aeration holes as ordinary conditions, not damage.

A green-reading system, created by Mark Sweeney, that reads break with the feet instead of the eyes.

Air density effect is the change in aerodynamic drag and lift a golf ball experiences as air gets thinner or thicker, from altitude, temperature, barometric pressure, and humidity. It has nothing to d

Three strokes under par on one hole — a 2 on a par-5, or a hole-in-one on a par-4. Americans also call it a **double eagle**. It's one of the rarest feats in golf, far rarer than an ace: it needs a hu

How a golfer's body and clubface are aimed relative to the target line — feet, hips, and shoulders should sit parallel to it, like the two rails of a railroad track, not pointed at the target itself.

A template hole defined by a blind approach shot played over a hill or dune to a green the player can't see. C.B. Macdonald and Seth Raynor copied it from Prestwick's 17th in Scotland. The original at

How steeply the ball falls out of the sky — the angle between its flight and the horizon at the moment it returns to landing height.

The highest point the ball reaches during its flight, measured in feet above where it started. It's the payoff of launch angle plus spin working together, and it tells you a lot about how the ball wil

The closely mown strip of turf that transitions between the fairway and the putting green, cut shorter than the fairway but longer than the green itself — also called the fringe or collar. Because it'

Whether the clubhead is traveling upward or downward as it strikes the ball, in degrees. Positive means hitting up, negative means hitting down. Irons *should* be negative (about −4° for a tour 7-iron

The band of attack angles that suits each club: downward on anything played from the turf, level to upward on a driver played from a tee.

A relief option that lets a player drop a ball anywhere along the straight line running from the hole through the spot where the original ball lay, as far back on that line as they like. Once the ball

Backspin is the ball's rotation around a horizontal axis perpendicular to flight, the spin component that generates lift, shapes trajectory height, and determines how hard a shot stops on landing. Tou

Ball compression measures how much a ball deforms under a standardized load, expressed as a number that runs roughly 30 (softest) to 120 (firmest). The standard test presses the ball between plates un

A golf ball's cover material sets how much it spins and how it feels at impact — the two dominant options are cast urethane and ionomer (often branded Surlyn). Urethane is softer and grips the clubfac

The physics governing where a shot starts and how it curves: the clubface largely sets the starting line, and the gap between face and swing path creates the curve.

A small, flat object — a coin, a tee, or a purpose-made disc — placed right behind or right beside the ball before it's lifted, so it can be replaced on the exact spot afterward under Rule 14.1. Marki

When a player's ball at rest moves after being touched by the player, a caddie, or equipment, but not by wind, water, or gravity — those carry no penalty at all under Rule 9.3. Rule 9.4 makes the defa

When part of the ball hangs over the hole's lip after a putt, the player gets a reasonable time to reach it, then ten more seconds to see if it drops, before Rule 13.3 treats it as at rest. Reasonable

Where the ball sits relative to a golfer's stance, front-to-back — the simplest setup variable, and the one that most directly controls low point and launch angle. The driver is played farthest forwa

How fast the ball is moving the instant it leaves the clubface, in mph. It's the single biggest ingredient in distance — every extra 1 mph of ball speed is worth roughly 2 yards of carry with a driver

A shot that climbs too steeply, hangs in the air, and drops well short of its normal distance — the signature of too much backspin, not too much loft.

A friendly-bet bonus won by making par or better on a hole after a shot has struck a tree. The name comes from the sound of a ball ricocheting off bark. A single barkie pays out when a golfer's ball h

Adjusting an iron's loft or lie angle at the hosel with a bending machine, fitting the club to a golfer's swing without changing the head. A bending machine clamps the head and levers the hosel to ope

A fine-bladed, cool-season turfgrass — creeping bentgrass above all — that produces the smooth, dense putting greens of the northern United States and the British Isles.