As JLS posted, if only thru 2nd and 3rd parties, or on the QT, most would be surprised at the numbers of players, coaches, umpires, refs, team doctors, dads/relatives of collegians that use the info and insider knowledge they have to wager..hell, it(wagers by particuliar parties) shapes many of the moves/drifts on certain teams & games weekly.
Or is anyone naive enough to think that all those ex-NFL guys at Vegas Super Bowl parties or representing Touts and Offshores, just suddenly came into the world of wagering after they exited the door as a player for the last time?
A few astute Book Managers that frequent the RX could verify that certain un-named customers with peculiar last names shape their numbers at times, as almost any local BM here can verify that a team doctor, collegian's dad, cousin,etc..can often serve up a Large press play with nice info or by choosing to make a monster bet.
The proliferation of Offshores have allowed for faceless and nameless 2nd and 3rd parties to post up as whales, while I'm sure quite a few pros(athletes not wiseguys) are the money played via their bearded buddies.
Insider Trading isn't just on Wall St..it's anything with a dollar attached to it!