Curtis Granderson and Jacoby Ellsbury have had a similar run the last few seasons. In 2010, both players were held back by injury, failing to succeed in their new roles in the way their teams envisioned. In Granderson's case, he missed 24 games due to a grade two groin strain, and didn't see his performance improve in his new pro-lefty environment as expected. Ellsbury was even worse off, missing all but 18 games due to broken ribs. Or not broken ribs. It depended on who you asked.
The Yankees and Red Sox wanted these players to come back and perform as they knew they could, but both did their respective teams one better and produced the best seasons of their careers. Granderson played all but six games, and hit .262/.364/.552 while smacking 41 homers and 77 extra-base hits. Granderson had power in the past, but now he had more of it. Ellsbury's homer surge came out of nowhere, as he went deep 32 times -- that's 12 more than he had in his career before 2011. He posted a .321/.376/.552 line with 83 extra-base hits, led the league in total bases, earned Comeback Player of the Year honors, and finished second for AL MVP.
These seasons were unexpected, but both players are young enough -- and talented enough -- that it's easy to envision them sticking at this level. That's been said about many a player before, though, and we all know that's not how baseball works. There are ups and downs, career highs and career lows; Ellsbury and Granderson have experienced all of those in the past two years.
The major change with Granderson was in his production against left-handed pitchers. He had been notoriously awful against lefties, as his career line prior to 2011 was .215/.274/.346. That's some replacement level production, but because he hit right-handers so well (.287/.363/.527) it's not like it dragged him down completely. Even with his injury and struggles in 2010, Granderson did improve against lefties somewhat. In 2009, his True Average -- which accounts for park, league difficulty, and other contextual items in order to present a single offensive value -- against lefties was .186. Replacement level TAv is .230, and average is .260, meaning Granderson was further below replacement level than that hypothetical player is from an average one. In a word, he was terrible against lefties.
For 2010, though, he was certainly tolerable, posting a .242 TAv against southpaws. It's tough to get excited about a single-season change like that, but Granderson built on that further. In 2011, Granderson posted a .327 True Average against lefties, actually doing better against them than the righties he's crushed for years (944 OPS vs. LHP, 902 vs. RHP).
How much of that can we expect him to retain? Lefties have career-best years against the southpaws who normally crush them fairly often, due to the small sample sizes involved. Like Granderson, many of them attribute it to a changed stance or approach, but saying so doesn't always make it true. Granderson's 2011 is impressive, but he faced lefties just 219 times -- that's roughly one-third of a season. Looking at the last 12 years (the seasons in which there is split data for TAv available), we get a sense of how much of this improvement is actually, well, improvement. This table shows lefty batters who saw at least a 50 point increase in TAv against lefties from one season to the next, then how well they performed in the last year of this three-year period:
|PA Year 1||TAv Year 1||PA Year 2||TAv Year 2||PA Year 3||TAv Year 3|
As a unit from 2000 through 2011, lefties who saw a Granderson-esque boost against southpaws in one season retained almost 40 points of the increase in the following year. Granderson has already had his three-year period in a way -- and added another 90 points of TAv in the last year -- which bodes well for him in terms of maintaining at least some level of excellence against his former nemeses.
Ellsbury also improved against left-handers, but he was never as poor against them as Granderson (.307/.359/.393 pre-2011, .284/.348/.492 in 2011). His 2011 had more to do with getting better at crushing anyone, regardless of handedness.
Ellsbury's secret to success was specific, though. Pitchers used to kill him with fastballs inside and low, as he didn't have the patience, swing mechanics, or power to drive them. If pitchers needed Ellsbury to whiff or make weak contact, challenging him with a fastball -- and focusing it low and inside -- was the key. Ellsbury ranked #16 in the majors from 2007 through 2010 in percentage of fastballs seen with 65.8 percent, alongside the likes of players no one is going to confuse for power hitters:
Pitchers didn't get the memo in time in 2011 to stop Ellsbury from being a power threat. He still saw 62 percent fastballs, good for #11 in the majors among qualified players. That's likely to change now that the league has had the off-season to see just what they did wrong against Ellsbury, but it's also not likely to stop his performance completely.
The 2011 version of Ellsbury was one with a different approach. He attacked and succeeded at crushing pitches he had not had much luck with in the past, in a way that exceeded even the most optimistic of his old scouting reports. Fangraphs' pitch value data is not predictive, but it does tell a story of what happened. Prior to 2011, Ellsbury had produced -0.5 runs against fastballs. In 2011, he was at +31.4 against heaters. If that doesn't bump him out of the top 20 in fastballs seen, then the league deserves what's coming to them.
Adjustments will only slow the tide, though, not stop it entirely, as Ellsbury has shown himself capable of driving just about anything thrown in his direction. If he "only" goes deep 20-25 times year instead of being a 30-plus homer threat, the Red Sox will find a way to accept him for who he is.
Granderson and Ellsbury might never replicate their 2011 seasons again, but that's what a career year is. These are two supremely talented center fielders who have shown us what they can do when they are at their very best. Given those lofty heights, even their second-best is going to be better than most.
Thanks to Rob McQuown of Baseball Prospectus for the research assistance.