For example, let’s take a look at an example from the Super Rugby semi final between the Crusaders and the Sharks which takes place on Saturday 26th July.
Saturday 26th July 09:35 Crusaders v Sharks
Handicap Betting: Crusaders -6.5 points 0.83, Sharks +6.5 points 0.95
The simplest way to think about this is before the match starts (ie. 0-0) the Sharks already have a virtual 6.5 point lead. Should the Sharks lose the match 27-20, they will get their 6.5 points added onto their score so the score will end up 27-26.5 which means that the Sharks lose that handicap bet. However should the score end 26-20 then the Sharks will win this handicap bet 26-26.5. If the Sharks win the outright match 25-20 they will still receive the 6.5 point head start and essentially would have won the match 31.5-20, the handicap bet of +6.5 will be a winner.
You will also notice that alternative handicaps are available for any given match. For example, there may be an option to back the Crusaders at -3.5 points and the Sharks at +9.5 points. The odds will be different to the +/- 6.5 line but the principle of one team receiving a head start remains the same.