If you keep finding it, keep playing it!

In my case, finding it can be half the battle!!! I can't remember playing a ball long enough to worry about it wearing out.

I have gone 90 holes with the same ball last year til I got road rash during 6th round. That was with an AVX!

I've been running an experiment on that subject for the last 20 years. For some reason I can't get through 3 rounds with the same ball, so the answer must be 2 1/2 rounds.

There have been some recent studies showing a significant impact to distance and direction when a ball has been scuffed. Very little study on overall cover wear but I have seen some on-line putting videos where a Matt finished ball, a dirty ball, and a new ball all rolled differently into a cup using a stempmeter type of devise. I also think the impact to distance and direction would be magnified by someone who hits the ball hard and long. Point being, if a beginner who struggles with contact and tends to loose a lot of balls anyway worries about taking a worn or slightly damaged ball out of play, it might not be as beneficial as a scratch player looking for their best performance. If you are the latter, maybe consider switching out an undamaged ball after the overall shiny coating has become slightly dull. Drop it into your practice shag bag and break out a new one.

My ball speed is far from 180 mph. For me, after my next paved cart path or tree mark that won’t wash off.

I love Don's answer and kinda agree with him. Titleist golf balls hold up well, even at the premium level (Prov1, Prov1x, AVX). As long as I can wash it and it maintains a nice shine, it is playable. Sometimes four rounds, as long as I am hitting down the middle. I mark my balls with a blue sharpie and when the blue wear off, it is time. Hakuna matata.

Honestly, from what I’ve seen, a modern ball is good to play as long as it’s not damaged physically.
During a competitive round, you may want to switch out for a fresh ball once or twice per 18, just to hedge your bets in case there’s some non visible damage to the ball which mainly comes from hard or sandy wedge shots. Casual or practice rounds, though, if it looks good and feels good, it’s probably just fine to keep playing.

Tough call... I don't lose balls that much and can go 72 holes often. But I agree with Dale... when the cover loses its sheen or shine (about 54 holes for me) I tend to take it out of play. The ball seems to pick up more mud and grass stains after the sheen/shine is gone.

I have been using the same three balls during the offseason in the simulator. So four months and I have not seen a significant decrease in performance. Using the PROV1X.

I have been averaging 3-4 rounds with my Maxfli Tour S balls. The Titleist rep was at my club last week and suited me up with a two ball sleeve of AVX’s and Pro V1X. First tee shot on Friday saw my new AVX slice off into the lake…..Oops!

There is data an studies to prove that a ball that is scuffed up will lose significant distance. There is also a factor that we are all not millionaires or tour pros getting free balls, so ya have to consider that. If you've played a couple rounds and its got some scuffs, i think it should become a practice ball. Use it to chip and putt with.

Keep it in play until it's scuffed or scarred and you notice loss of distance or odd ball flights due to spin.

Not that any of you would ever buy something other than a ProV... Haha
But I highly suggesting steering clear of the Brooksy ball ZStar Diamond. It scuffs and damages so easily. I went through multiple balls around. It would scuff and then begin to spin off the planet.... It could last maybe 2 wedge shots... I hit one ball straight into the fairway (not my fairway, but still fairway...haha) I went to pick it up and it had a huge scuff on it... tossed it into the bush. ONE HIT...

It makes you really appreciate what Titleist does, there's a reason why it's far and away "The #1 ball in golf."