The largest playing field for any ballgame is the one for polo. The maximum allowable length is 300 yards, and the maximum width is 200 yards. Therefore, a polo field can cover a total of 12.4 acres.
From The Giant Book of More Strange But True Sports Stories by Howard Liss. Illustrations by Joe Mathieu.
https://en.wikipedia.org/wiki/Polo#The_field
The Wikipedia article notes that polo fields are about 10 acres in size. I don’t know if that’s because the rules concerning field size have changed, or if there is simply a preference for a smaller field even though it could be larger.
We have several polo clubs here. The matches are open to the public but I’ve never gone to watch.
We had one about 5 miles from where I grew up that Ginger Baker would play at so lots of Cream fans would show up just to see him.
The image of Rock God Ginger Baker playing polo is quite the juxtaposition.
“Well, he liked hitting things…”