Why Sox have drawn a line on Hamilton

The Red Sox to date have drawn a line in the sand on free-agent outfielder Josh Hamilton, apparently unwilling to go beyond three years in a deal for the 31-year-old slugger.

Is that a wise assessment by Boston brass? We crunched some numbers to find out.

Hamilton will be 35 by the time he reaches a potential fourth year of a contract. In his past three seasons, playing in hitter-friendly Texas, Hamilton has batted .313 with an on-base percentage (OBP) of .370, a slugging percentage (SLG) of .583 and an on-base-plus-slugging percentage (OPS) of .952. He also has hit 100 home runs in that span, an average just over 33 per season.

What is the likelihood that he will maintain that level of production at age 35? I went to the incomparable baseball-reference.com for help.

Since the start of division play in 1969, 36 players had an OPS of .900 or better while playing at least 100 games at the age of 35. From 1969 to 1995, an arbitrary season to mark the start of the Steroid Era, there were only 9 players who had an OPS of .900 or better at age 35, including Boston’s Dwight Evans, who in 1987 had a .986 OPS, hitting 34 home runs in 154 games.

Beginning in 1996, 27 35-year-olds had an OPS of .900 or better, including 15 players with an OPS equal to or higher than Hamilton’s three-year average of .952. That list includes Boston’s David Ortiz, who had a .953 OPS in 2011, when he hit 29 home runs in 146 games.

How about in recent years?

In the last three seasons, only 14 35-year-olds played 100 or more games. Only 20 35-year-olds played as many as 75 games. I was surprised that the number was that low (In 2012, there were 19 players 35 or older who played 100 or more games, including two 40-year-olds, Raul Ibanez and Chipper Jones. A total of 51 non-pitchers in that age class appeared in at least one game).

Of those 14 who played 100 or more games, Ortiz was one of just three 35-year-olds with an OPS of .953. The others were Lance Berkman (.959, 31 HRs) and Paul Konerko (.906, 31). Use .850 as the cutoff, and you can add one more player, Scott Rolen (.854, 20 HRs).

Only three more players had an OPS of .800 or better: Carlos Beltran .842, Vladi Guerrero .841, and A.J. Pierzynski .827.

The numbers suggest, then, that the Red Sox have a reason to proceed with caution if they are even contemplating offering Hamilton a fourth year. Few players, obviously, continue to be productive at age 35, and that number may shrink if we are indeed entering the post-steroid era. That doesn’t even take into consideration what physical toll years of substance abuse have taken on Hamilton’s body, although he played in 148 games in 2012, second most in his career.

A recent case study involving a Sox player might also explain the team’s reluctance to sign a player through age 35, a hesitation, by the way, that was not present when they signed Carl Crawford and Adrian Gonzalez.

Outfielder J.D. Drew had just turned 30 when Theo Epstein signed him to a five-year, $70 million deal. From ages 29 to 31, which includes his first season in Boston, Drew’s line was .279/.389/.474/.863, with 46 home runs. In the next three seasons, which took him through age 34, Drew’s line was .270/.379/.495/.874, with 65 home runs. Very comparable, right? Except, Drew’s OPS, which was .913 at age 33, fell to .793 at age 34. In 2011, at age 35, Drew was hurt, played just 81 games and had an OPS of .617. He retired after the season.

No two players are the same, of course. Ortiz at age 36 was having his best season since 2007 when he strained his Achilles tendon, cutting his season short at 90 games. The Sox decided that he can continue to be productive, and remain on the field, when they gave him a two-year contract extension.

But at the dollars Hamilton is seeking, it’s understandable why John W. Henry has drawn a line.

Alex Speier on WEEI.com did a similar breakdown using a few different numbers and came to the same conclusion. Check his analysis out here.