In a horse race I am interested in the horse 'Hidden Jewel' not because of its form or a tip because I believe its price is too high and thus the price will shorten.
My potential loss is zero, I cannot lose on this race, it's a punter's nirvana; all I have is 100% upside. The £24.55 is now spare for me to do with as I wish. As things stand, I will win £24.55 if 'Hidden Jewel' wins and if it does not win I will lose nothing.
If I wanted I could now oppose 'Hidden Jewel' with no liability. This is because I already have 'free' money at my disposal on this horse this would enable me to have a 'green' P&L, i.e. no losses meaning that whoever wins the race guarantees a profit.