What's Zito worth, or: thanks for nothing, Adam Eaton

It's been said elsewhere, but Adam Eaton's deal with the Phillies has set the early bar for this offseason's free agent pitchers. The Phillies will pay Eaton $24 million guaranteed over the next three years and an option could push the value to $33 million over four years. Here is what Eaton has done over the course of his career:

Year  PRAA   ERA+    IP
-------------------------
2000    6    103    135.0
2001    0     93    116.2
2002   -2     71     33.1
2003    0     97    183.0
2004  -14     87    199.1
2005   -5     90    128.2
2006   -2     92     65.0

PRAA is a Baseball Prospectus metric that stands for Pitching Runs Above Average, and it's similar to ERA+ only weighted by innings pitched. Eaton has been better than an average big league pitcher only once in his career -- his rookie season -- and he wasn't even a whole lot better than average. He has never thrown two hundred innings in a season. A league-average pitcher who can eat innings is still a valuable commodity, but Eaton can't even be counted on for that. He is a below average, injury-prone pitcher who will be paid a king's ransom for the next three or four years.

Now Mr. Zito:

Year  PRAA   ERA+    IP
-------------------------
2000   20    174     92.2
2001   15    125    214.1
2002   34    169    229.1
2003   18    129    231.2
2004   -3    105    213.0
2005    4    116    228.1
2006   17    116    221.0

Okay, the obvious: Barry Zito is a better pitcher than Adam Eaton. Zito has, at times, been a very good pitcher, and he has always been an innings eater. He has thrown at least 213 innings every season in which he has been a full-time starter, his ERA has been better than league average in each of those seasons as well, often well above average. A big concern with Zito is that he has been considerably worse these past three seasons compared to his established level of performance from his previous three.

Zito's worth will vary depending on whom you ask. In a sane world, $12 million or so would be more than fair market for his services. In a world where Adam Eaton will make $8 million a year, who's to say that Zito isn't worth $18 million? Then, Johan Santana must be worth $30 million.

Plus, look at those two pictures. Zito is at least $10 million dreamier than Eaton. Eaton is so frumpy.