I don't believe so, I have a free bet of $100.
If the horse loses, I lose nothing, if it wins, I win $100, or $96.50 less commission.
The profit on the $100 back bet @ $5.00 is $400 (386 less comm)
The profit on the $100 lay bet @ $4.00 is $100 (96.50 less comm)
So if the horse wins the race I win $400 but payout $300 on the lay - I win $100
If the horse loses the race, I lose $100 on the back stake, but win $100 on the lay stake - no win/ no loss.
Essentially I have a free bet on the horse of $100 @ evens
Now to green up my position I divide the profit ($100) by the lay odds ($4.00) and have a $25.00 lay bet on the horse in addition. Thus whichever horse wins, I win money.
A lot less, but no risk. - yes, AFTER greening up I win $25.00.
But what about the other lay bets matched?