Let me answer your question Craps Master, I will say this, I have not seen the movies or read the book that have jumped the M.I.T. team into superstardom. I am answering this on my experiences with them. M.I.T. was originally started at the college by a professor and his students, I know their names but believe it to be inappropriate to post them here.
They started a business/corporate like structure called "Stratigic Investments" (I actually obtained a copy of their handbook by greasing a front desk person at their hotel to get me into their room). Anyway when M.I.T. hit town, they were very good and had perfected team play to a science. They would hit with several groups at one time in one casino, This would overwhelm surveillance and pit personnel. Then they would hit like this all over town, using aliases, disguises in some cases. If it wasn't for some minor slip-ups on their part, it would have been harder to positively identify them.
But the one thing they would do and continue to do is bring in fresh faces. Also with Gaming everywhere, they can run smaller curcuits and not hit the same one for a while, this keeps them in action. As the M.I.T. group is very good, in fact excellent there have been many great teams both before and after them.
When it comes to backing off a losing player, I have only done this a few times, determining the player was a threat but hit a dry spell (it was better to get rid of them, instead of worrying about them later) but I have seen the Pit do this many times.