Maybe you heard that some guy named Jason Heyward made the Atlanta Braves' Opening Day roster. It could have something to do with the sound of the ball coming off his bat, which was a daily discussion at Champion Field in Orlando, Fla. Or maybe it was all those cars that Heyward dented with his devastating drives over the right-field wall.
But more likely, it had to do with how Heyward -- despite being all of 20 years old -- has dominated every minor league station and seems ready for the majors. While toying with minor league pitchers, he constantly showed his trademark patience -- he had 105 walks to 138 career strikeouts, an elite strikeout-to-walk ratio for a young prospect. He also showed more power as he advanced, an excellent sign for his future.
There have been some recent prospects who came to the majors with similar pedigrees at this young age. But a quick scan of their debut seasons might be reason for pessimism regarding Heyward’s upcoming season.
Under-21 debut seasons since 2000.
Not quite the list that an Atlanta Braves fan would want to see. But this is why age factors so prominently in the appraisal of prospects -- the fact that Miguel Cabrera could come up at age 20 and even put up a slightly above-average season at the plate meant that his future was bright. But if he put the same season up four years later, there would not have been much reason for excitement. So the fact that Heyward will create an entry for himself on this list is almost as important as his results.
But there are also reasons to expect better from Heyward. His minor league walk-to-strikeout ratio (0.76) is miles better than Miguel Cabrera’s decent 0.5 minor league number. His .190 career minor league ISO (slugging percentage minus batting aveage) is barely bested by Justin Upton’s .193 and Delmon Young’s .200. So to put Heyward’s skills in focus, relative to other recent young debuts, he’s got plate discipline better than Miguel Cabrera along with power comparable to Justin Upton.
Eno Sarris is an author of FanGraphs.