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Josh Hamilton: 32 Is The Number

For a 31-year-old outfielder, we have surprisingly little information about Josh Hamilton. 3000 or so plate appearances, three full seasons, and he’s already on the long side of thirty. We all know the reasons why, but it leaves us looking at his different peripheral metrics — all oscillating — and wondering which number should get our focus. None of it might matter as much as his age, on the other hand.

It’s not all bad. Hamilton set career highs in isolated slugging percentage (.292), home runs (43), runs (105), and full season walk rate (9.4%). He hit more home runs per fly ball than he ever had (25.6%), and his line drive rate remained above-average (and above 21%), as it has every year he’s played in the big leagues. We shouldn’t get too wrapped up in his September / October failure (a “terrible” .245/.330/.543) if he’s going to continue being a high-average slugger with center-field eligibility, right?

The most worrisome peripherals (in both fantasy and real-life baseball) concern his strikeout rate, and that is the one late-season split that adds weight to the post-peak side of the ledger. Hamilton struck out 34.9% of the time in the last month-plus of the season. He also struck out over 30% of the time in June. For the season, he posted his career-worst swinging strike rate (20%) and strikeout rate (25.5%).

We’ve written about this some before. In the past, Hamilton has kept his strikeout rate near average (19.7% career) despite a poor swinging strike rate (14.9% career) by being aggressive. He was so aggressive that he got a pitch to hit before he could strike out, perhaps. At least, that’s the theory behind him being an outlier on the graph relating swinging strike rate to strikeout rate. And David Cameron did a good job pointing out the flaws in his approach this year, and the fact that Hamilton only made minor adjustments this season. Last but not least, Jeff Zimmerman aged batting components and found that strikeout rate began to rise after 30.

None of that paints a pretty picture about Hamilton’s ability to make contact going forward. And, since he was already an outlier when it came to strikeout rate compared to his swinging strike rate and plate discipline — he has swung at 38.7% of pitches he’s seen that were outside the zone, almost ten percent higher than the league average over his time-frame — you’d be right to worry about his strikeout rate (and therefore his batting average) going forward.

He has always had a nice batting average on balls in play. Last year, his .320 BABIP helped him to a .285 batting average despite striking out over a quarter of the time. His career .335 BABIP suggests that he might continue enjoying that sort of help, and lo and behold, his 2012 xBABIP was almost identical to his actual result. And even if line drive rates have poor year-to-year correlation, the fact that he’s had a line rive rate over 21% in every season suggests that it is a skill he owns.

But a 20% swinging strike rate is difficult to overcome, even with good batted ball results. The swinging strike rate in baseball has been rising, but if you look back at all the seasons since 2002, when we started tracking swinging strike rate here, Hamilton’s 2012 number is tops in the category. It’s not particularly close, either. Miguel Olivo‘s 2011 (19%) and Mark Reynolds‘ 2009 (17.8%) serve only to highlight Hamilton’s whiffitude.

The top 50 seasons by swinging strike rate produced a .265 batting average. But that includes a hefty amount of 14% whiffers. If you limit it to the top 25 (15.3% swSTR as the floor), your batting average drops to… .264. That small difference is probably due to the fact that power is correlated with whiffs, and also helps your BABIP and your batting average (think of the difference between a line drive landing in the infield versus one that lands in the outfield).

So Hamilton’s power, and line drive stroke, will help him reduce the negative effects of his declining strikeout rate. And the fact that last year’s strikeout rate was almost six percentage points worse than his career rate — a fact that suggests that some regression to his career levels would offset his age-related decline — that’s also a mitigating reality. And so you can easily return to many of the power-related career-highs he set last year and dream upon a better strikeout rate in 2013.

But then you can’t forget that he’ll be 32 next season. And that’s post-peak by any aging curve.