Johan Santana still feels like a disappointment, but shouldn't

The bad news:

Year   K/9 K:BB
2005: 9.25 5.29
2006: 9.44 5.21
2007: 9.66 4.52
2008: 7.53 3.22

As you can see, the strikeout rate fell off a cliff this year, but the K:BB has been in continued decline since its peak in 2005, when he was 26 years old. Of course, even though he still came into this year on the good side of 30 he'd thrown over five normal-starter-seasons worth of innings in his last four years, so it wasn't unreasonable to expect (as a lot of people did) a falloff this year.

And fall off he did, but how badly?

Year    ERA  OPS  GB:FB
2005   2.88 .594   0.91
2006   2.77 .616   1.06
2007   3.33 .678   0.92
2008   2.75 .652   1.14

Those metrics paint a much prettier picture of Santana's Mets debut. The groundball improvement isn't massive, and he's still miles from Webb/Lowe territory, but it's enough to suggest that more of the lost strikeouts turned into weak dribblers than warning track flies.

A translated ERA metric would be helpful in dealing with the differences in home park and league/opponent quality, and it's probably safe to assume that both factors would make the comparison to the Minnesota years slightly less favorable, but BP only runs those figures annually so I don't know how much.

They do, however, keep VORP updated daily, and that metric (which measures how many fewer runs a team surrendered while a given pitcher was on the mound than they would have if those innings had been pitched by a minimum salary scrub) is adjusted for park/league effects.

So we can look at this list of the top 10 most run-preventing pitchers in the majors and conclude that, even though Omar failed to swoop in on Cliff Lee this spring when the Indians barely wanted him to show up to camp, he didn't exactly screw up when he ponied up for Santana:

59.4 Cliff Lee
56.4 Roy Halladay
53.9 Tim Lincecum
49.1 Johan Santana
48.6 Brandon Webb
47.3 Dan Haren
44.6 Ryan Dempster [!]
44.2 Jake Peavy
44.1 Ben Sheets
42.9 John Danks