According to DAS rules they will provide you with a market for FAV vs FIELD on any race you request. This market is gauranteed to be set to between 106-108% (how often do you see this??).

There is a catch however, if they quote you a market you have to have a bet on either the field or the favourite (it would seem this only applies to the telephone bettors).

You will notice their fixed odds are generally called pre-post until 20 mins prior to race when it switches to normal fixed odds. This is probably when they post a market for this bet type?

If you're good at it, you can see the advantage though with the very good % bet.