Not an engineer, but I've used the same ProV1 (a lucky #7) now for my last 4 rounds, with no loss of performance or distance.  My record last year was 7 consecutive rounds (before finding the cart path on back to back drives).

I played premium 'tour' TM balls before, and the best I could manage was a few holes before their covers were damaged from iron groove 'bites'.

We might have a variety of answers on this one.  The Players' strength and skills would vary and that would have different wear effects on the ball- I think.  

As for me, I don't hit the ball hard and my wedges doesn't do much or any damage on the cover, however, the shine and its white tint or tone is something I notice that makes me retire the ball from play, although I'll keep them for chipping around.

I think this would be a very difficult question for Titleist to "officially" answer.  I'm not an expert, but I would think storage in between rounds would affect the lifespan of a ball as much as anything (other than bouncing off a cart path or something like that).  I could be way off base, but I would think a ball stored in low humidity at a normal temperature would last longer than a ball stored in high humidity or an extreme hot or cold spot.  For the normal golfer, I would think a ball should be able to go at least 3 or 4 rounds without any noticeable effects.  And as long as it's not bouncing off of something hard and your wedges aren't too aggressive, I think it would last much longer for the "average" golfer.  At least in my mind, the ball is going to perform at a high level longer than I will be able to use it without losing it!

No official answer here, but in my personal experience I normally can play 3 rounds with a ProV1x. In a tournament I won't use one more than a single round though, not because of performance, more visuals than anything rather than re-marking my faded dots & line. 

I will use a ball until it cracks, or can't read the lettering. It's a way of challenging myself to play a ball and not lose it for several rounds. My record is 13 rounds
 

This is awesome!

This is awesome!

[/quote]Bryce - we Aggies (Class off '79) still alike, it seems. LOL

As a junior player I normally play 3-4 rounds with one but depends on what happens to the ball 

Regarding shelf life, I have a friend who is still playing ProV1X's that have the 2007 US Womens Open Pine Needles logo on them. There is no observable loss of performance after 8 years.    Except of course, for the improvements that have been made to the ProV1 and ProV1X  over that time period. 

I use 2 to 3 a round but may use the same balls again for a few rounds... any loss in green-side spin and I use a new ball.

Lost a Pro V1x yesterday on a perfect drive on the fairway under a pile of leaves... was so upset I used my "found balls" reserve of Pro V1 and a Trusoft yellow for the other 10 holes I played

8 years seems like a long time.  I found that when I had "new" balls that started getting to that age and above, there was a noticeable difference.  I'd be curious to see how one of his 2007 Pro V1x's compares to a new Pro V1x.  In theory a new model should perform better simply because of the improvements made over the years.  But I'd be curious to see how big of an improvement would be seen.

Yeah, I wouldn't believe it if I hadn't witnessed it firsthand over the past 2 years. I will check with him and see if we can perform an on course comparison.  I have to believe that we will see a positive difference when he uses the newest model.  I'll post our findings.