Betfair have a new deal on their multi’s. If you make a five way multi bet before the 25th of Jan, then if you only get 4 of the multi’s correct, then betfair will refund your stake. Put simply, its a good deal.
If for example, we bet on five tennis players at 1.10 and lets assume that there is an 89% chance that each one of them will get up, this gives the bookmaker with a 2.1% edge.
However, the chances of all five coming home are 0.89^5 = 56%. The chances of four getting home is 5 * 0.89^4 * 0.11 = 34.5%. The odds one would get multing five 1.10 players together is 1.61
Hence, the expected return from a $20 bet is equal to $4.89. That means you have a 24% edge using the free return of the bet if four get through.
Only $20 can be refunded, and the bets have to be all on tennis. Click here to bet with betfair.
With over ten years of live betting history on the net, and large profits almost every year, the Sportpunter AFL model is the best anywhere to be seen. More than 10% ROI had been made and is on sale now at the 
Sportpunter's tennis model has been one of the longest running. Operating since 2003 it has made around 5% ROI over the years. And with many matches being played, it is a model that tennis betting enthusiasts need behind them.
Is that $20 per bet? Or $20 all up?
its a multibet, so a $20 bet. If you are not a member, sign up above. If you are, you should have got an email with a link where you have to opt in.