Fyldewhite
Tour Winner
Depends on the conditions I'd say. The ground has to be soft(ish) to take big divots and these should knit back quite well provided they are well trodden down. In really soft conditions you should hardly be able to tell it was ever removed. Problem may be that a dry spell would mean many not replaced properly (and many golfers like with pitch marks pay only cursory attention to doing a good job) will just curl up and die. Overall though I'd guess the success rate is pretty good so definitely worth doing.