Grooves channel away moisture and debris so the clubface can “bite” the ball, that bite is friction, and friction is SPIN.
Case Study #1 - Mud in the Grooves (Launch-Monitor Test)
Test: Today’s Golfer put mud in a 7-iron’s grooves and compared to a clean face on an iron...
Results (dirty vs. clean):
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Backspin: 2,566 rpm vs. 5,399 rpm (≈ –52.5% spin)
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Ball speed: –7 mph
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Peak height: –20%
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Descent angle: –16.3% (flatter)
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Carry: +3 yards (but far less stopping power)
What it means: You might gain a couple yards, but you’ll lose control—the ball comes in flatter and releases. That’s how good approaches become 15-foot comeback putts.
Case Study #2 — Wedges in Wet Conditions
Test: MyGolfSpy’s Wet Wedge Test (over 17,000 shots).
Results: In moisture, wedges lost ~35% of dry spin on average, with the worst cases >60% loss.
What it means: Dew, rain, and rough moisture are spin killers—especially on partial wedges where you need check.
Case Study #3 — Moisture Combinations (Coach Test Data)
Test: Andrew Rice/GOLF.com measured a wedge in different wet/dry combos.
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Dry club + dry ball: ~6,603 rpm
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Wet club + dry ball: ~5,463 rpm
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Dry club + wet ball: ~5,291 rpm
What it means: Any moisture between face and ball cuts friction and spin and increases launch. Dry/dry is best for bite.
If you want to increase your spin rates, you must clean your grooves with the Caddy Splash golf club cleaner! Shop now.
Don’t Confuse “Dirty” with “Worn”
Dirty grooves are a maintenance issue; worn grooves are a replacement issue. Titleist’s Vokey team found performance tails off significantly as grooves wear (roughly the equivalent of ~75 rounds, depending on use/conditions). If your wedges are old and smooth, cleaning won’t bring back all the spin.
If you want to increase your spin rates, you must sharpen your grooves with the Caddy Splash golf club groove sharpener! Shop now.
Clean vs. Dirty: What You’ll See on the Course
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Spin (RPM): Dirty/wet faces commonly reduce spin 30–50% in tests; wedges are hit hardest. Expect more rollout.
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Launch & Peak Height: More launch + less spin = higher flight that doesn’t grab.
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Descent Angle: Flatter landings = less stopping power near the pin.
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Distance “Gain”: You might occasionally fly it a touch farther, but with unpredictable release—not a good trade.
How to Keep Spin High (Simple Routine)
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Wipe after every shot. Remove grass and moisture immediately. (Pros do this because it works.)
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Re-wet, then scrub. A small amount of water helps lift debris; scrub with nylon bristles (safer for faces than harsh wire).
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Clean the sole, too. Sole buildup changes turf interaction—clean it every time.
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Deep-clean post-round. Mild soap + soft brush; dry thoroughly to avoid rust.
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Inspect wedge faces. If the grooves look rounded/polished and you’ve logged a lot of rounds, consider replacement.
FAQ
Q: Do clean grooves add distance?
A: Not the goal. You may even see similar carry—the win is spin and stopping power
Q: Is this just for wedges?
A: No. Even a 7-iron lost ~52% spin with dirty grooves in testing. Wedges are most sensitive, but mid-irons are affected too.
Q: What about rainy days?
A: Moisture reduces friction. Keep a towel handy, dry the face, and clean grooves before each swing; expect ~35% average spin loss if you can’t remove moisture.