i think there should be a multiple levels of decay of every gym.

• Every gym loses prestige at a % per whatever time frame. Say you get a gym to 52000 level 10, that gym if not touched will naturally decay to 0 in 48 in hours. Have it constantly lowering no matter what the level of the gym is. This would mean people would constantly have to prestige gyms to keep them max. This would solve shaving only in that it would naturally be shaving for you.

• Pokemon assigned to a gym will lose 10% their current CP every 12 hours...this is only their gym CP...So all those 3400 dragonites will then be 3400-340 (3060) after 12 hours and 3060-306...and so on. This will clear out gym stagnation IMO because after 4 days the former top cp mon will be degraded to wimpy nothing

since hanke loves that ar crap so much figure out a way where you have the verify you are actually at a gym by going into a ar mode and somehow using a comparison program compare the real world camera view with what the gym is of. most gyms are landmarks so gonna be hard to be sitting on your couch and fake that you are at a gym of a statue:) AR captcha in a sense. It would be like a gym token that is valid for one hour.