If that is really a worry then you can try the following (if you are able to place lays close to the off). Place a bet on the favourite early in the day. Don't lay. A lot of the time (not always) the odds will come down on the favourite and laying nearer the off will give you a nice profit if it does win. Remember you get a free bet if your horse loses so you only need to cover the £4 loss (assumes you convert a £20 free bet to a £16 return), so if the odds have gone up near the off you have lots of wriggle room (this method is a bit of a punt, but I did this on all the favourites last year and was better off in the end)