A buddy of mine, good advantage player told me about this earlier. He said the square move is to pile into the pick six with a big investment. Put a couple bucks on it like a lottery ticket and maybe get lucky is all he suggested. The sharp move is to bet the races, especially the later races in the pick six. You get so many square bettors from all over showing up trying to pick winners that all race pools are inflated with their money outside of just the pick 6 with lots of them chasing money after they have lost hope on the pick six, plus later on you get hedgers inflating the win pools unreasonably. Its a great cocktail for value plays, especially the place and show pools where he's made some good scores with minimal risk.
Thing he hates most is if you win the big prize, you have to pay tax on it which pretty much negates any overlay edge you think you are getting from the carryover.