One reason I love large breeds is for play fighting a lot of people don't agree on it cause it teaches dogs to be aggressive. My mastiff I started slowly from the time I got him. He is very friendly with everyone. He understands that when I play with him we can go all out but when anyone else plays he don't make a sound. He will growl bark an jump using all his weight to send me flying an will grab my hand or arm an hold it in his mouth applying pressure till I say drop it. My last dog was a rotti/akbash mix he was 150 an stood close to six feet standing on his back legs I did the same with him an he was a very friendly dog but protective at night. I'm just wondering your thoughts with play fighting to hear what some other people say.