With the fav. there is a lot of liquidity so it's not so easy to manipulate the horse's price, if we are patient and confident we can make 3 or 4 ticks on each trade, making it much more profitable.
P.S: It's very important to stay out of the lay side of the fav. close to the post time! If the race goes live we can loose a lot of ticks in seconds.
Have a G-Day!