So they simply bet on sports results after thoroughly researching the odds? Where is the hedging in that?
Of course, it might happen that as the match going on, the draw is more and more likely, so the odds for a draw is getting lower. Then at some time, the trader can still bet on a draw (like in the first example), but this time he will have a loss, but a lot lower loss as if he would place just only one bet and lost. And that's I think is called hedging, you bet on all outcomes in different time points.
That is not hedging; hedging is the process of considering (at the point of purchase) how you can protect your investment against unquantified events. For example you might decide that Apple as a company is undervalued so you want to buy some of their shares, but the markets seem volatile at the moment so you want to hedge yourself against large movements in the index.
You can do this by selling short on the index at the same time as you buy your Apple shares. So suppose you're correct about Apple (that they're undervalued) and the market realises this and their share price increases by 1% relative to the index, without your hedge this could see your investment say gain 4% if the index goes up 3%, or lose 2% if the index falls by 3%, so you get either +4% or -2%.
Now suppose that you have your index hedge in place, if the market rises by 3%, you get 4% on Apple -3% on the index = 1%, if the market falls by 3% you get -2% on Apple and 3% on the index = 1%. So either way you get the 1% profit through your Apple intuition. By selling the index you've hedged yourself against movements in the underlying market.
So to hedge a bet on something like Roger Federer winning against Rafael Nadal in a match today, you need to try and find something else to bet on at the same time. I can't really think of how to do this though.