My parents are dealing with something similar (albeit in the 'burbs). There's tennis courts right behind their house, and the proliferation of pickleball has made the courts a popular spot. Honestly, it's very annoying. The pickleballers start at 8am and play until the sun sets, and while the clack of the paddles is annoying, the real annoyance is the constant shouting during games. Pickleball requires absolutely zero physical exertion, so you can sustain a conversation while playing, but you're not close enough to each other to speak at a normal volume so people just have shouting conversations the whole game. Tennis doesn't have this issue because you're actually running back and forth across the court. It's really hard for me to have sympathy for a Chestnut Hill NIMBY issue, but pickleball might be what makes me sympathetic.