A few days ago, we offered this column  on Josh Hamilton  and the likelihood of diminishing returns in the fourth year of a contract. In light of the fact that the 31-year-old (who will turn 32 early next season) signed a five-year, $125 million deal with the Angels, it seemed appropriate to update the numbers to examine the standard performance of comparable hitters as 36-year-olds (Hamilton’s playing age in the fifth year of a deal), particularly given that, as Rob Bradford reported , the Sox were only interested in Hamilton on a deal of three or fewer years.
Hamilton is the 60th player since 1901 with an OPS+ (meaning OPS compared to league average but adjusted for park, with 100 representing 100 percent of league average, and 130 representing a player who is 30 percent better than average) of between 130 and 140 during his age 27-31 seasons and at least 100 homers during that time. As a group, his predecessors have seen their OPS+ drop from an average of 135 to 122 between ages 32-34 to 111 at age 35 before bumping back up to 114 at age 36.
However, the availability of those players into their mid-30s has seen considerable declines. While there were 60 players in the initial “Hamilton class” between ages 27-31, there were just 38 players who remained active at age 36. Meanwhile, of those who did play at age 36, those 38 players averaged 391 plate appearances, broken down as follows:
500-plus plate appearances: 12
400-499 plate appearances: 9
300-399 plate appearances: 4
200-299 plate appearances: 7
100-199 plate appearances: 3
1-99 plate appearances: 3
So, of the 60 original members of the Hamilton group, and excluding the six who remain active but younger than 36, just 38.9 percent have been healthy and productive enough to claim as many as 400 plate appearances at age 36. Players who are elite in their primes tend to remain productive (albeit considerably less so, and with far less power) as they age into their mid-30s, but their ability to stay on the field at age 35 and 36 tends to drop precipitously, to the point of creating the possibility of a very expensive contract albatross.
Here’s the breakdown of hitters in the Hamilton class: