I heard about this and it makes alot of sense. If game is tied (generally will be 3-3 or 7-7) and game is lined 17 at haftime, bet the over. If both teams come out and score a TD than it is still tied and you need a winner, so 17 pts in second half is almost guarnteed for a minimum score 2nd half and that is a push, anything else wins. Hope I explained that well and get ready. Not something earth shattering but I would think above 53%. Must be 17 or lower and bet 2nd half over.