Perhaps the reason why they are labeled as players is the very fact they play people around. Lets not talk about amateurs. Women have their intuition to spot these a mile away. The over-exaggeration acts and overly sweet talks. These are amateurs.

The good ones is where the problem starts.

Off the top of my head (without experience) perhaps someways to check is to

a)Talk to his friends, not just one but a few. Ask them how they got to know him and in doing so you might find out more about him.

b)Make a note of how often he gives gifts? I don't know but IMHO affection shouldn't have a cumulative price attached to it. It's nice to get surprise gifts, everyone likes gifts but are they coming in waaay too often and really extravagant gifts?

c)He falls very fast and very hard for you. This at first is flattering. But think about it - is it normal? In a normal relationship, a man or woman moves at a gradual pace to "get to know" the other person. They will call up for a date, if the date goes well, they will ask for a
second date. They will probably call you prior to the second date (they should, anyway, to make arrangements). But if they start calling or text messaging you every day after that first date, it's not normal. Don't be flattered, be wary.

d) and lastly FYA: http://www.baggagereclaim.co.uk/how-to-spot-a-player-playa/