USGA on U grooves: Impact on GCA?

[Brent Hutto]

"...and high spin taketh away iron carry distance". (from the low swing speed player).

Are you sure about that and if you think you are what empirical evidence are you basing that on?

Yes, I'm sure.

I've played a couple hundred rounds with high spin balls and a thousand or so rounds with low spin balls on the same golf courses. I'm pretty sure the high spin balls carry at least a couple yards farther with the driver but I'm absolutely certain the same high spin balls fly several yards shorter with irons.

That pattern is exactly what is predicted by the software that's available for modelling golf ball flight aerodynamics. So when the math predicts the same thing that I see with my own eyes that's plenty good enough for me.

[TEPaul]

Brent:

I feel exactly the same way about the driver (and iron) trajectories of the old high spin rate ball by high swing speed players fifteen and more years ago compared to the driver (and iron) trajectories of the new low spin rate ball by high swing speed players today. Like you my eyes aren't lying. Tech also seems to suggest that at the same swing speed (ODS) it could be up to 30 yards more carry distance today.

But one interesting point may be that a higher spin rate ball may give a low swing speed player more carry distance off a driver, particularly if a higher spin rate ball may give a high swing speed player less carry distance off a driver.

[TEPaul]

Brent:

On the other hand, from my in person observations, this young man from Nebraska who has the highest ball speed the USGA has ever recorded in person did hit his driver fairly low so I don't know what to say.

And as a reference when he really caught one in neutral conditons it did fly on a fairly low bullet like trajectory and CARRIED app. 320-340.

I wonder how far he would carry the ball with one of those initial high trajectories that most of the others have?

I asked him why he hit it so low and he said because there is so much wind in Nebraska and he broke his "optimized" driver he hit it higher with.  

[Jim Sweeney]

TEP:

The television announcers made quite a bit of noise about Mickelson's hitting the ball lower to gain accuracy, but he has remained among the leaders in distance. At Riviera lower was better due to the wind and f&f, of course.