With the advent of more betting exchanges you will have a far greater chance to do some arbing yourself, rather than entrusting your money with anyone else. Personally there are great opportunities to arb on the tennis between Pinny and Betfair, and the beautiful thing with Betfair, is that if you have a lean to a side then you dont have to place your entire arb there before the match starts, you can wait until after it starts and bet in the run, or hedge half ( or the fraction youre comfortable with ) before the match starts, and let the other half run for as long as you like.
As a rule, I prefer to make my own decisions when it comes to sports as in the end I wish to be solely responsible for any losses that I incur. Dont get me wrong, I will listen to people whose opinions I value, but generally that only involves matches I have already selected for potential wagering. They generally will not make me instigate a play, but moreso affect my staking. I have no problem taking advice or paying more credence to stock tips, as the information is far more specialised, but when it comes to sports I prefer to be the soul judge in the end.