Moisture punishes some covers far harder than others
In dry conditions the cover advantage is already clear: MyGolfSpy measured roughly 1,900 rpm more spin from the average urethane ball on a 35-yard wedge shot, and more than 3,200 rpm more on a full dry wedge. Introduce water and the gap widens rather than narrows, because ionomer sheds spin at close to twice the rate. MyGolfSpy's test hub puts it plainly: on a wet full wedge, the ionomer balls gave up nearly a third of their spin.
The more useful finding is that 'urethane' is not a guarantee. Within the urethane group MyGolfSpy recorded a spread of over 1,600 rpm on the 35-yard shot, with the Bridgestone Tour B XS described as essentially unaffected when wet while the TaylorMade Tour Response and Snell PR4 struggled to hold spin. A companion MyGolfSpy piece reports the Srixon Q-Star Tour holding almost 95 per cent of its full-wedge spin in the wet. Same cover material, materially different behaviour once the ball is damp.
Verified Data
Source: MyGolfSpy.
This is why golfers switch balls by course and by season
Most UK and Irish golfers already change ball through the year without much data behind the decision — a firmer, lower-flighting model for a windy links in autumn, something softer and higher-spinning for soft summer parkland greens. Today's Golfer's 2026 62-ball robot test makes the same point from the testing side, noting that external factors including wind, temperature and altitude all influence how a ball performs and can lead you to play a specific model.
The wet-wedge numbers give that instinct a figure. If your ball loses close to half its greenside spin the moment there is dew, rain or a damp lie involved, that is not an edge case in Britain and Ireland between October and March. It is most of the golfing year, and it shows up on precisely the shots where scores are decided.
Fit the ball to the conditions you actually play in
This is the case for fitting over marketing in one number. A ball chosen on a dry range in July, or chosen because a tour player uses it, is being judged in conditions that may not resemble the ones you play in for half the season. Cover material narrows the field; individual model data decides it, and the wet column matters as much as the dry one.
KaddieIQ does not sell golf balls and has no brand to defend. BallFIT is free, brand-agnostic, and built to point you at the model that suits your speed, your short game and the courses and conditions you actually face — which for a lot of golfers means accepting that the right ball in August and the right ball in November are not necessarily the same one.