I spend about 80 or 90% of my golf time at the range or practice areas (green and trap) so I see all of the above from time to time. I have to say though, that the unwritten rule of three practice balls on the green is adhered to more often than not. It's usually someone new that will dump 15 on the green and go to town. It's annoying, but I bite my tongue because one of the cranky old regulars will invariably emerge from the cigar smoke-choked grillroom, stroll up with his putter and his drawstring Chivas Regal bag of practice Dunlops, and set the newbie straight.