Jacoby Ellsbury’s Excellent Aging Curve

A lot of people don’t trust speed-and-defense players to age well. They’re one knee injury away from being worthless! Once the speed goes, what’s left! Just look at what happened to Carl Crawford! The skepticism over the value of production that is not hitting is never more evident then when a player like Jacoby Ellsbury hits the free agent market. While some might grudgingly admit that Ellsbury has had a couple of terrific seasons lately, his lack of power and dependence on his legs have created some doubt about whether he’ll be able to be an impact player for much longer.

Is such skepticism actually warranted, however, or simply another instance of hitting being overvalued relative to other skills? Rather than just lean on conjecture, let’s actually look at how players with similar skill sets and performances at Ellsbury’s age have done after they turned 30. To find a good set of comparable players, I looked at all outfielders over the last 30 years, then narrowed down the list to just players who were in the same general range of production as Ellsbury during those three seasons and had a significant part of their value come from defense and baserunning.

Including Ellsbury, I found ten outfielders who matched this skillset and performance to a pretty high level, and have actually completed their age-36 season, so that we can compare their performances over a seven year period, the length of contract I expect Ellsbury to land this winter. Here is the table showing Ellsbury’s performance relative to those age-27 to age-29 peers.

Name	AVG	OBP	SLG	wOBA	wRC+	OFF/600	DEF/600	WAR/600
Lenny Dykstra	0.312	0.400	0.428	0.373	134	28	11	6.2
Jacoby Ellsbury	0.303	0.356	0.469	0.359	123	23	12	5.8
Rickey Henderson	0.285	0.387	0.450	0.374	133	33	2	5.7
Kenny Lofton	0.324	0.381	0.474	0.372	118	20	11	5.0
Tim Raines	0.297	0.395	0.461	0.371	135	30	-3	4.8
Andy Van Slyke	0.271	0.341	0.451	0.352	126	19	6	4.7
Ichiro Suzuki	0.328	0.374	0.440	0.350	118	17	6	4.4
Devon White	0.253	0.314	0.402	0.322	98	2	18	4.1
Steve Finley	0.279	0.331	0.406	0.328	106	6	10	3.7
Marquis Grissom	0.286	0.337	0.435	0.336	100	2	12	3.3

OFF/600 and DEF/600 are simply the number of runs created through offense or defense per 600 plate appearances, and then WAR/600 is Wins Above Replacement per 600 plate appearances, so that we see each player’s totals on a scale that is roughly one full season’s worth of playing time.

In terms of total production, Ellsbury was actually better than most of these guys over the three years being measured, even though he missed half a season during his age-28 season and had limited production when he did manage to play. His production in his two healthy seasons was so great that it puts him in the top tier of these types of players even with his mediocre 2012 season included.

Overall, these players give us a pretty decent group of outfielders who were productive at this stage in their careers despite moderate power, primarily succeeding through excellent baserunning and tracking down balls in the outfield. Devon White, Marquis Grissom, and Steve Finley were more defensive specialists than total all around stars, but it’s still informative to see how guys who were more defense and less offense did as they got older.

Including the three lesser hitters also helps serve to balance things out, so that the total production of the nine players we’re looking at nearly matches Ellsbury’s own production. Overall, the average wRC+ posted by these players in their 27-29 seasons was 119, just a little below Ellsbury’s 123. They were approximately nine runs above average defensively per season, while Ellsbury was 12 runs above average per season. Not every player matches Ellsbury perfectly as a comparison, but as a group, these guys comprised most of the same skill levels as he does now.

So how did they do from their age-30 to age-36 seasons? I’m glad you asked.

Name	AVG	OBP	SLG	wOBA	wRC+	OFF/600	DEF/600	WAR/600
Rickey Henderson	0.287	0.418	0.453	0.393	148	40	-2	6.0
Lenny Dykstra	0.285	0.401	0.440	0.374	126	21	5	4.6
Ichiro Suzuki	0.332	0.377	0.426	0.348	114	16	5	4.1
Kenny Lofton	0.287	0.368	0.422	0.349	107	8	10	3.7
Andy Van Slyke	0.280	0.354	0.434	0.350	117	12	-2	3.2
Tim Raines	0.284	0.376	0.408	0.352	116	15	-6	3.0
Devon White	0.272	0.332	0.435	0.336	100	2	8	2.9
Steve Finley	0.275	0.338	0.476	0.349	110	8	-3	2.3
Marquis Grissom	0.264	0.304	0.413	0.311	84	-13	-1	0.7

Grissom is the warning sign that people often point to, as his performance regressed to the point that he was barely worth playing, and he produced little value after age-30. Of course, he was also the worst player of the comparable age-27 to age-29 group, so perhaps we shouldn’t be too surprised that he was also the worst player beyond age-30.

Lenny Dkystra and Andy Van Slyke could also be pointed to as moderate warnings, or at least reminders that future health is not guaranteed. Both Dykstra and Van Slyke were pretty effective players even beyond age-30 when they were on the field, Dykstra managed just 1,600 plate appearances and Van Slyke just 2,300 after their age-29 season. We don’t see the precipitous decline in production with either of them that we do with Grissom, but they failed to age well because they weren’t able to stay in the line-up often enough, and both were out of baseball by the time they were 35.

The other six, though? Pretty obvious success stories. Henderson got better, even as he moved to a corner outfield spot full time. Ichiro maintained almost all of his value, staying basically the same player that he was in those first three years. Raines and Lofton both got worse, but both were still excellent players even after their speed began to slip. Devon White and Steve Finley, despite starting from lower baselines, actually hit better after turning 30, and the increases in offense helped to offset their defensive downgrades, leaving them as productive regulars for the bulk of their age 30-36 seasons.

Overall, these nine players maintained an average of 70% of their ages 27-29 WAR/600 rates. If you apply that 70% rate to Ellsbury’s +5.8 WAR/600 from his last three seasons, he’d forecast as a +4.0 WAR per 600 PA player over the next seven years. Even if we include the players whose careers ended early, the group of comparables still averaged 522 plate appearances per year over their 30-36 seasons. Take 70% of Ellsbury’s last three year performance and project it out to 525 plate appearances per year and you’re still left with a guy who averages +3.5 WAR per season over the next seven years.

The idea that Ellsbury-type players fall apart as their speed declines is simply exposed as a myth. Players like this that have come before have simply made adjustments to compensate for their declining speed, and have continued to produce at a high rate even as their speed and defense diminished. Don’t buy into the idea that Jacoby Ellsbury is headed for a crash as he slows down. In fact, if he performs like the average of the similar players who came before him, the rumored price tags of $120-$140 million might end up proving to be a bargain.