From Blaseball Wiki
Outdoorsy is a Player Modification first seen as a result of the Outdoorsy Blessing in Season β19.
Outdoorsy, according to its description, makes Players with it play worse in less Grandiose Ballparks and play better in more Grandiose Ballparks. However, descriptions are liars and not to be trusted, as Outdoorsy's true effect is a boost of 20% * g, where g is the numeric value of that Ballpark's Grandiosity with g = 1 being a full bar. g cannot be negative, so it is in fact impossible for Outdoorsy to confer a debuff.
Outdoorsy was first offered in Season β19 with the Blessing of the same name, which was won by the Tokyo Lift and went to Kline Greenlemon.