+1! Any tugging and it is time to toss IMHO!!
I do keep count with dice, don't need to, but just a reminder that usually 6 is about the limit before I seem to get a little pulling. I knew 6 was showing on the dice and thought that the last shave it seemed strong but the 7th wasn't as nice. Might also have been that I had 4 days growth instead of the usual 2 to 3. I did get a nice shave with very little irritation which surprised me by the way it felt on the first pass.