We interrupt regularly scheduled programming to discuss a theme that appeared in yesterday’s comment thread comparing Matt den Dekker to Grady Sizemore. Both centerfielders are in the 6’2″, 200 lb range, play center field, bat left-handed and were born in August. Sizemore is just five years older. Leave aside for a moment that Sizemore has not had a full, healthy, productive season since 2008, but he was a dramatically better prospect, ranked #9 in baseball entering 2004 by Baseball America.
Sizemore made his Major League (21) debut at a younger age than den Dekker made his professional debut (22) in the GCL. In the season in which he turned age 23 in 2005, Sizemore was hitting .289/.348/.484 in 158 games for the Indians, and picking up down-ballot support for the MVP (he finished 23rd). In the season in which he turned 23, den Dekker played in 32 professional games between the GCL and Savannah, and hit .336/.396/.459 with no home runs in 32 games.
By the summer in which the two players turned 24, Sizemore was an MLB All-Star who finished 11th in the MVP balloting on the strength of a league-leading 53 doubles and 28 homers as part of a .290/.375/.533 line. In the summer he turned 24, Matt den Dekker graduated from advanced-A to double-A with a combined .265/.337/.460 line.
How about at double-A? Sizemore played double-A in the summer in which he was 20/21 and hit .304/.373/.480 with 26 doubles, 11 triples and 13 homers. den Dekker played AA in his 23/24 season and hit .235/.312/.426 with 13 doubles, 3 triples and 11 HR in 72 games.
The age matters. It always does. This is not unfairly penalizing Den Dekker, who chose to start his career later by returning to Florida to improve his draft stock. To baseball’s detriment, the last three years of Sizemore’s career have been a tremendous disappointment as injuries have robbed him of his once elite talent. Comparing a prospect to one of the more electrifying young players at his position in the last decade is a good way to get into trouble.