Stats Don’t Prove Ramon Santiago Hits Better in a Limited Role

It’s the line we’ve been handed for several years now by Jim Leyland and others: Ramon Santiago is simply not a major league starter. He does well in limited playing time, but if you start him too much he’ll likely wear down and his production will drop sharply.

We even had the discussion a few days ago on this very blog after John expressed disappointment to see Ramon on the bench and Danny Worth starting in his place. Even with Adam Everett gone and a rookie replacement, it seems that Jim is sticking to the notion that Ramon is not fit to play every day.

But is there any truth to this idea? Does he really hit better when he’s able to rest in between games?

Over the last three seasons in Detroit Ramon has garnered 615 plate appearance and hit for .329 wOBA (below average, but not bad considering he plays defense at a high level). Breaking it down year-by-year, he hit .388 in 2008, .304 in 2009, and is hitting .320 this season (again, wOBA).

In order to find out if he’s better with rest I took the game logs from those three years and eliminated games in which he had played the previous day. In 2008 his rested wOBA was .351, in 2009 it was .289, and this season it’s .254. They all average out to a three-year rested wOBA of .297. Each rested number is decidedly lower than its counterpart.

But maybe limited playing time encompasses more playing than one game on a day of rest. What if we expanded the numbers to include back-to-back games while eliminating games in which he’s played the previous two days? Using this expanded data set, we come up with wOBA numbers of .397 in 2008, .301 in 2009, .319 this season, and a three year average of .329. Here we find our first number of somewhat limited time that is better than his overall totals. Ramon was able to hit nine wOBA points higher in 2008 when playing in no more than two games in a row than his season average.

Unfortunately we still don’t see a trend of better-than-average production in limited playing time situations. His 2009 and 2010 numbers are slightly lower than his overall numbers for those years, and his three-year average from this data set is identical to the overall three-year number. […]

He’s obviously not hitting better in a limited role in a game-by-game sense, but what about big picture? Does he wear down over the course of the season? If so, we would expect him to hit worse as the months progress. His numbers do, in fact, reflect this trend. His monthly career wOBA numbers are as follows:

Other than a surprising resurgence in September and October, he is indeed trending downward later in the year. The problem here, though, is sample size. Because Ramon has only had one season in his career in which he’s shouldered the full-time starter’s load of games (2003), he’s not yet accrued even 350 plate appearances in any of the above month groups. 350 may seem like a large number, but wOBA can randomly fluctuate with a standard deviation of .025 at this plate appearance total. If we take this into account, we find that all of his monthly averages are within one standard deviation of his career total. Unfortunately, this means the downward trend has little significance; it can be explained due to randomness just as easily as the wearing down effect.

His monthly numbers from his only full-time year, 2003, also dispel the idea of a month-by-month decline. That year, he hit for the same wOBA in July as he did in May (above his season average), he hit poorly in August, but then had his best month in September. If evidence existed to support this type of decline, it would surely show up in 2003.

It still isn’t impossible that his production would see a decline in a starter’s role, but we don’t have any solid statistical evidence that this is actually happening. Until we have a large enough sample size to prove the opposite, I’m forced to conclude that his true hitting skill is not significantly changing with his playing time.

(For more information on wOBA and what the above numbers mean, check out this Fangraphs post.)