[danup note: I found this lurking in the back-end. Suck it, SB Nation blog software. That Brad Penny pitchf/x post was nowhere to be found.]
preliminary matter: is derek jeter smoking crack? word is that the yankees are offering him a 3y/$45m contract, which seems on the generous side of just about right. at this point jeter is a 3 win shortstop, which is nothing to scoff at, but not something meriting . . . oh, 4 or 5 years at $23-24m.
derek did have an outstanding 7 win year in 2009, but that appears to be in large part due to a defensive metric anomaly: for the last eight seasons, derek jeter has been a negative value in the field. except in 2009, when he suddenly was worth a positive 6.4 runs in the field. this occurred at the same time he had a decent season with the bat. in 2010, he had a collossal dropoff, hitting only .320 in wOBA.
in fairness, that could just be bad luck; jeter has a .357 lifetime BABIP, yet had a .307 BABIP in 2010. going into a year 37 season, however, it's probably not time for clubs to just assume that he'll continue to pull in .360 or .370 wOBAs until he's 41 or 42. his diminished BABIP may be due in part to slowing down as he ages - thus beating out fewer groundballs. he also hit fewer line drives last year than ever (16.1%) and more grounders than ever (65.7%). the larger point is that jeter is right at the age when almost everybody begins to decline. if you review the top 500 seasons by war at B-R, you'll see very few entries from the 37and over category: barry bonds has a number of entries, cy young has two,phil niekro has one, ted williams has one, and dazzy vance, a righthanded pitcher for the brooklyn robins, in 1928 was worth 9.0 wins. the non-chemically enhanced category of 37+ year olds comprises just 1% of all top WAR seasons.
now, obviously, jeter doesn't have to be worth 8 wins to be worth a contract for $23m or $24m. the larger point was that the aging curve gets pretty steep right now. betting on a 37 year old to be better than average next year is chancy. betting on a 37 year old to be a 5 win player for the next three, four, five years is just stupid.
one of the things we're in the market for is a second left-handed reliever. there's lots of reason to think that we overvalue LOOGys. i think it would be a big waste to spend any major chunk of money there. needless to say, i think it's very likely that we will drop a chunk of money there.
it look that the dodgers are going to non-tender george sherrill. he had a vomit-inducing 2010 by most metrics -- he went from a 1.70 ERA in 2009 to a 6.69 ERA in 2010; a 3.21 FIP to a 5.20 FIP; a 4.16 xFIP to a 5.61. xFIP.
this should be a cautionary tale, first off, in relying on one season samples with relievers. relievers pitch so few innings one season is not enough time to reduce the luck factors to a meaningful level. it should also be an extra caution against trying to use single season traditional stats on relievers: sherrill's jump from 1.70 to 6.69 in ERA in a single season should show how unstable and non-predictive the ERA stat is. while his more advanced stats showed greater stability, there was a big shift there as well.
the biggest change was that sherrill's walk rate went through the roof -- he allowed 5.94 BB/9. still, again, with the instability in single seasons for relievers. sherrill's career walk rate is 4.42. however, he's had three seasons of 5.50 BB/9 or worse. he's also had four seasons of 3.50 BB/9 or better. the kicker: he's only had seven seasons in the majors. i doubt the reason is that he's the jekyll/hyde of the loogy world. i suspect that he's really pretty much the same pitcher from season to season; he just has huge swings from one year to another due to luck.
we love to have these big arching narratives in neat season-long packages for relievers, even though the season is not really a meaningful sample for them: brad lidge comes to mind here.
anyway, the original point i was getting at is i still wouldn't give sherrill more than $1m or so. the point i ended up at instead was that you should never just look at one season with a reliever to figure out what his talent level is.