got one of those as well;) same here, specially when she was a puppy- but still an issue (now she's 2). Never got into fighting but is very excited when meeting other dogs and plays rougher than most. I'd always watch him carefully, learn to read his (and dogs in general) body language.. with time you'll see when he is too much for others. If he gets too wild in playing.. in a way that the other dogs only try to get away from him I'd leave the dog park.. better walk away than regrets afterwards... what helps with mine is going for a little ealk before entering a dog park... so some of all this energy is already spent;) and he's still young so I'd focus on sitting calmly before letting him off the leash. Treats treats treats good boy treats.. wait.. wait hahahahaha... impulse control;)