Notwithstanding the recent shellacking of the Cards at the hands of the Mets, the rotation this season has performed admirably. Much discussion has been had about making Todd Wellemeyer a member of the bullpen or the disabled list and promoting one of several starting candidates to fill his slot. Now that we're almost at the midpoint -- well, a couple starts short of the midpoint for the three pitchers who've not missed a start -- of the season, it seems time to take stock of what we have.

There's some stunning information here. These are our original five projected starters. What we have are basically two aces . . . and yes, one of them is Joel Pineiro. Lohse and Wainwright are turning in solid work and Wellemeyer is lagging far behind.

I want to first credit  chuckb's post from December, which I admired greatly. I intended this to be an update of sorts from what we saw then.

Here, I'm trying to use old standbys (ERA) to establish a comfort level for folks who don't want to learn a new acronym every week; the established stathead measurement (FIP), and some of the interesting (though still controversial) data from statcorner. One of the criticisms for FIP is that it may undersell good pitch-to-contact types, since it ignores batted balls that don't go for home runs entirely. tRA seeks to be a next-gen FIP, trying to account some of the batted ball metrics. Now, tRA remains unproven. tRA addresses what the pitcher has actually done, while tRA* winnows out what the pitcher is actually responsible for (and hopefully what he will do in the future). Rather than further expose my ignorance on tRA, I will crib shamelessly from chuckb and give you links to a simple explanation and a complex one. tRA+ is a scaled metric like OPS+ to league average where league average is 100.

The reason we're interested in league average is because of Matt Carruth's article looking at what defines a role for pitchers -- e.g., is pitcher X a #2 or a #3 type pitcher? Recall as you consider these numbers that Carruth's numbers are 2008 standards applied to 2009 stats. I would not expect them to change tremendously year-by-year, but I imagine it is possible.

The average for an ace in 2008 was a tRA of 130 -- that means pineiro is comfortably an ace, and carp is . . . cy freaking young. granted it's only 9 starts, but this is amazing. looking back at chuckb's post, carp's tRA makes him better than every single free agent pitcher last year, including CC Sabathia . . . even better than just Sabathia's second half in Milwaukee! Okay, folks, let's all say it together: standing pat on what was last year a replacement-level pitcher and getting a pitcher that comes off the DL was like making TWO off-season trades for two aces without giving anything up . . . .

You know, it really is.

Wainwright is running a little behind last year -- right on the boundary line between being a #2 and a #3 by tRA+. Lohse is running a little ahead of his great year last year, and grades out right on the boundary between a #3 and a #4. Worth noting is that FIP likes them the same so far this year -- both are at a 4.07 FIP, well above the league average of 4.33. Wellemeyer is actually a quite decent #5 -- average tRA+ for #5's in 2008 was 76.

tRA* likes pineiro to regress . . . to something like aj burnett last year! on the other hand, the gap between his FIP and his ERA suggest that he's been a little unlucky. I'm guessing he'll regress somewhat, but it would be hard to complain about the results either way.

tRA* actually likes waino, welly, and lohse to IMPROVE modestly. The tRA* projection for carp is hard for me to understand -- i'm guessing it probably comes from assuming league average performance during years when he hardly pitched at all. I would just disregard carp's tRA* at this point.

the other open question here is health, as always. when will kyle come back? will he be healthy and effective? will carp stay healthy? will someone else go on the DL?

The sore thumb in this group in terms of quality of performance is Wellemeyer. He is the only one performing significantly below average. The question is whether we would be better off with somebody else. The next group to look at are the major league subs and the minor league cast (obviously, there's overlap here).

*Please note that the ERA, FIP, and IP include relief pitching as well as starts, while the tRA, tRA*, and tRA+ are only for starts. Hawksworth's stats are all for relief, since he has not started a game in the bigs yet.

The sample size for basically all of these guys in the majors is too small to tell. So, let's also bring in their minor league stats, as well as those of the other memphis starters. These numbers actually tend to confuse the issue more, rather than pointing to a clear candidate

Thompson had 3 great starts at Memphis by traditional measures. However, tRA didn't like the starts as much, and tRA* HATED them. Boggs had a mixed set of eight starts, and he's got almost the same tRA* as Thompson. If you're inclined to credit tRA*, this suggests that a lot of Thompson's success at the AAA level was luck; his BABIP against in Memphis is .254 for 2009. On the other hand, he has pretty poor stats in the majors in 2009, and his BABIP against for St. Louis is .265.

The remaining non-Ottavino candidates -- the Hawk, walters, and mortensen -- have had quite good seasons at AAA. FIP really likes Walters and Hawksworth. I'm struck by the comparatively poor reviews Mort gets from all the non-traditional stats. I would have thought tRA would like him a lot more. If you'd asked me before looking, I would have called Mort the closest thing to an ace on staff. But you have to acknowledge that this is a great staff; only Ottavino is well below average.

tRA* doesn't clarify things either. Mort gets a modest edge over Walters and the Hawk. Thompson and Boggs get relatively poor marks.

Honestly, dealing with these small sample sizes at two different levels, I can say nothing based on these numbers about whether Todd should be replaced, or by whom -- except that the pride of Team Italia, Adam Ottavino, should not be allowed near the rotation this year. Wellemeyer is not sinking this ship, but there's some suggestion that any one of the other five Memphis candidates could hack it as a fifth starter and maybe do better. My personal non-numbers-based prejudice is that Thompson has historically faired poorly when asked to do more than spot-start. I would rather see one of the other four get a(nother) chance at starting. I will note that Boggs has a BABIP against of .386 at the major league level and is thus likely to do better in future outings, rather than worse. I think Boggs is probably our first candidate, but I think there's ammo here to support giving Walters another chance, or giving the Hawk or Mort a chance.

The last comment I would have is we need to think about what we do with pineiro at the end of the season, if he continues to pitch like an ace. He's having a career year, but not the classic "everything-is-falling-my-way" year. Instead, he's made a turn around in how he pitches - a dramatic one that clearly is responsible for his success. I can't even think about a comp for a pitcher who drastically changes his repetoire with great success in his age 30 season. How much do we trust that success to continue? What will the market be for him? Will he want to stay with Dave Duncan and take a pay cut to do so? Do we offer him a contract? Do we not offer him a contract but offer arbitration? This, ladies and gents, is a nice problem to have.