Tip share is bogus. It only serves to allow employers to pay busboys and cooks less money. Those folks are not on the 2'13 per hour scale and the tips I have always left were for the WAITRESS/WAITER for their service. I have stopped tipping alltogether due to tipshare.
If I think my booth is very clean and I want to tip the busboy I will. If I want to tip the cooks I will. To me, those services are part the bill I pay for the meal. A curteous waitress that never lets my drink glass go empty is worth a tip. But she aint going to get one from me when I know that her employer is going to take that tip and split it up with other folks that did not intend to tip at all.
Tip share is a form of socialism in that a work group will all get equal share of tips made, so then while a waitress busts her a$$ and the busboy slacks off(or the other way around) the each get the same cut. Pi$$ on that noise.