This is an American size L. I purchased this at the Dodgers Stadium shop in 2004. It's unusual for a uniform shirt, as the numbers and such are embroidered. As shown in the last photo, there is some staining due to aging. Hideo Nomo, whom Shohei Ohtani also admired. Speaking of Nomo, the number 16 comes to mind, but this is a uniform from the time he wore the valuable number 10.