@George,
OT doesn't count in spread betting George. If you recall I have mentioned the matter and KJ referred to the ESPN giving a win to the side in a tied game which was the underdog on the spread.
In our game goals are more difficult to score than TDs in NFL and draws, ties, are common. Thus they are an aspect in a betting market. Usually priced at 5 to 2. This allows the price for winning to be greater than it would be if the draw was taken out of the equation. Which it can be. A 3-way market would look like A--7 to 4, B--2 to 1 and 5 to 2 the draw. If the final result, which side gets the cup, say, it would be 4 to 6 and 5 to 4. The punter having the choice.
Spread betting operates in many ways. Total points say. Adding up the shirt numbers of scorers. A total points bet would never count OT.
In horseracing a dead-heat is settled by dividing the stake in two and the full odds paid on both winners to that half. The other half being lost.
Having said that I suppose actuarially OT could be counted but it is a settled habit of the betting industry not to.