Nick Swisher: More like Bread, Less like Wine
Tom Szczerbowski-USA TODAY Sports
The more I look into the data, the more proof I get that players just don’t do all that well into their 30’s. Sure you have guys like Barry Bonds that had really, really productive seasons on the south side of 30. But for every one of them, there seems to be 10 more that flamed out.
The Mariners are somewhat likely to land Josh Hamilton or Nick Swisher in the next few weeks. There is little doubt that either player will improve the Mariners’ offense this year, the next year, and probably even the year after that. However, neither player is likely to sign for only three years, so let’s take a look at a longer-term projection.
Using Baseball-Reference’s similarity scores, I gathered both Hamilton and Swisher’s top 10 comparable players (up to and through the age-31 season). I then analyzed the average performance of those ten players in each subsequent season on the downhill side of 31. I looked at the effects of age on these types of players in terms of plate appearances, BABIP, OBP, ISO, Bill James’ Power-Speed statistic, and WAR.
I analyzed Hamilton on Monday, so here we go with Nick Swisher.
The first thing I noticed about Swisher’s comps was that they played fewer seasons after reaching age 31 than did Hamilton’s comps. The median for Hamilton’s comps was 6 years, while Swisher’s best friends only made it 4 years past the age-31 season. In other words, if Swisher is as much like his most-similar players as Hamilton is, then we should expect him to flame out sooner into his 30’s than Hamilton.
As we expected based on the information above, Swisher’s comps saw their stats decline over the years. The chart below summarizes the average decline each year.
While Hamilton’s cronies declined just 0.36 WAR on average, Swisher’s declined by half of a win! Logically, this may have something to do with the fact that Swisher has put more wear and tear on his body. Swisher was called up during his age-23 season for the Oakland Athletics, while Hamilton was prohibited from playing in the majors until his age-26 season. It could be that Hamilton’s injury issues more than make up for his decreased service time, but I don’t have any hard evidence for that. What I do know is that Swisher’s best comps did not last long, and they retired or declined quickly after their age-35 seasons.
Let’s take a look at a 6-year projection for Swisher, with a starting value of $5M per WAR, a 7.5% inflation rate, and the assumption that he plays in 2013 how he played between 2010 and 2012.YearPAWARValue ($)
That looks pretty ugly unless Swisher is willing to go 4 years for $40M. But obviously that’s not going to happen. However, one thing about Swisher’s comps as alluded to above, is that the real drop off came after four years. In other words, the aging process wasn’t linear at all. In fact, on average his comps actually maintained value for their age-32 through age-35 seasons. This probably has a lot to do with plate discipline and patience. Swisher and his comps derive a lot of value from plate discipline, summarized nicely by Swisher’s career 13.2% walk rate and .361 OBP. Those skills hold on a little longer, so maybe the following projection is fairer.YearPAWARValue ($)
With pretty constant value for four years, and then sudden drops, this version of Swisher looks like a candidate for no more than 4 years at $60M. In fact, Fangraphs crowdsourcing projected a 4-year contract at $56M.
What these two quick studies on Hamilton’s and Swisher’s comparable players have shown me is that the aging process is very real and very harsh after a player’s age-31 season. Even a good player. I know it’s important to get a bat, and overspending a little would be worth it to get a few more wins around here. But if the M’s absolutely have to go five years to get Swisher, I hope it’s for no more than $65M. I would prefer 4 years at $55M!