On big races like the Triple Crown series or the Breeders Cup, what you get 4 or 5 minutes out is generally what you will get at post time simply because of the size of the pools being bet into. With the day to day grind what you see 10 or even 5 minutes out is almost irrelevant to where the price will end up. MF is correct in why the odds change after the race. Bets are being taken right until the gate opens, and most tracks update odds on a 30 second interval so if the previous refresh was the second before the gate opens, the final update may not occur until 30 seconds into the race, which can look bad to the average player. Horse racing most assuredly has it`s corrupt features, most specifically with trainers and drugs, but the changing of the odds after the race starts isn`t one of them.