I have started betting on sports though I'm not very expert on the sport but because there are users who were sharing their tips, I followed their bets hoping they are right to their prediction.
Each sport has its own thing, you can't really compare tips for a game with tips for like my favorite, horse racing!
For example, I mostly go for combinations of trainer and jockey, you can't do that for basketball.
I normally stick with a few yards and jockeys and only bet on those events, I avoid groups 4-5 and low handicaps because they are truly unexpected and one horse having just done his best can easily beat the others by 10 lengths so they are as predictable as some 5th regional league!
The best way to tack a tipster if you really want one is to track his past history, see if he's in profit not just because he won 2 events at high odds and lost 20 others, and look for someone constant that plays roughly the same odds and events and doesn't just put bets now for $1 and then for $200!