This is part of my frustration in finding boarding. I consider good turnout to be a 1/2 acre with grass. The places that have this are few and far between in central-eastern MA, and I’ve run into multiple people that try to tell me their 20x20 paddocks are fine. A 20x20 paddock is an outdoor stall. I refuse to put my horse in a paddock that is less than 60x60- a horse should be able to make a 20m circle for crying out loud. Because I live in New England, things get muddy in spring/fall, so even if you find a place with a 1/2 acre turnout a horse might not be able to run in it because of the footing. Ideally the paddock would be managed to keep grass, so it wouldn’t get muddy, but unfortunately it’s more likely in MA that someone put 3 horses out on that 1/2 acre and never rotated or seeded, and the horses ate it down so it’s 1/2 acre of dirt. And in the spring, that means it’s a 1/2 acre of mud.
I finally settled on my horse having a large, dry paddock in order to move somewhere with better hay/water and care. It is on a hill, and a bit rocky, but he’s older now so he’s not doing a ton of running.