Now if only I had access to BP's MORP figures

Carlos Zambrano's last four seasons have all been 200+ IP seasons (average IP = 215, with PRAR (Pitching Runs Above Replacement) scores of 78, 91, 77, and 85, equaling an average of 82.75 for the last four seasons. He's getting $12.4 million this year. Let's take a look at the top pitchers signed in this offseason as free agents, not counting Matsuzaka or Gil Meche, for (hopefully) obvious reasons.

Carlos Zambrano
215 IP Avg, 82.75 PRAR Avg
1 year, $12.4 mil
$12.4 mil/yr

Ted Lilly
170.5 IP Avg, 52.5 PRAR Avg
4 years, $40 mil
$10 mil/yr

Jeff Suppan
194 IP Avg, 48.25 PRAR Avg
4 years, $42 mil
$10.5 mil/yr

Vicente Padilla
167.5 IP Avg, 45.75 PRAR Avg
3 years, $34 mil
$11 mil/yr

Jason Schmidt
204.25 IP Avg, 76.25 PRAR Avg
3 years, $47 mil
$16 mil/yr

Barry Zito
223.25 IP Avg, 68.75 PRAR Avg
7 years, $126 mil
$18 mil/yr

As you can see, the only comparables on this list for Zambrano are Zito and Schmidt. They all average 200+ IP/yr, and Zambrano has been a much better pitcher for the last four years than either. Zito may not be in a state of decline yet, but he certainly will be soon. Definitely before seven years are up. Schmidt certainly is, as his last four PRAR yearly totals are 94, 94, 45, and 72. Zambrano shows no signs of slowing down yet, and he's only 26 (Zito is 29, and Schmidt is 34). Better to throw an extra $1 mil to your ace pitcher than go to arbitration, and have a better chance of having him stay in Chicago for another few years. At any rate, he seems to be a steal this season at $12.4 million, especially given his IP track record. As they say in MVP, "This guy's a horse. When he's on the mound, the relievers usually get the night off."