It wasn't a study of one; it was of a whole decade of players, as I recall. But I was inviting you to try the method. You'll find that the vast majority of players show almost no improvement in their OBP past age 25 or so, which is the earliest point that they could show a significant sample size. The figure that sticks in my head is .012 BP points on average, which is a rounding error. Many players post-age 25 OBPs decline, about a quarter to a third, as I recall. I cited Mays as an example because i knew for a fact that his post-age-40 OBP went up, but there was too much decline built in overall for him to be the counter-example I was expecting him to be. Since I don't have the study handy (it was on some stats site, of which I subscribe to several, and it was at least a year ago), I'll have to settle for stating that I think anyone who think Baez is capable of improving his OBP from here on in is thinking wishfully, not realistically.