clock menu more-arrow no yes mobile

Filed under:

tRA...for starters

First of all, my thanks to Sky Kalkman over at BtB for today’s thread idea. and much of the data used in today’s thread.

Saber-friendly websites and new ways of measuring baseball performance are becoming more and more common every day. Indeed, the evolution of numbers themselves is baseball’s version of prescription drugs – every day there’s a new one you can’t pronounce and don’t know what the hell it does. It takes more than watching the evening news to understand them. Well, a new stat for measuring pitching performance was developed this summer by the folks over at statcorner. Sky’s brief tutorial can probably do a better job than I could of explaining it.

But the most advanced pitching statistic available just popped up this summer over at StatCorner, although there has yet to be a study to show that it's actually better than FIP or xFIP or even ERA. (Many people assume it is, though.) It's called tRA and uses eight categories of outcomes that are strongly under pitcher control: Ks, BBs, HBPs, HRs, GB%, LD%, OF FB%, and IF FB%. In one sentence, tRA credits pitchers for their ability to induce those eight events, without caring about the actual outcomes of the balls hit into play. And everything's park-adjusted. For a longer explanation, read this. For a no-numbers explanation, try this.
The purpose of tRA is to best determine a pitcher’s true skillset. A lot of pitching, like hitting, is luck. Pitchers often have the misfortune of having an unusually high number of their fly balls leave the park. Maybe they pitch a disproportionate share of their games in high (or low) run-scoring environments. Maybe they happen to pitch in front of a poor defense or, like the ’08 Cards’ rotation, in front of a very good defense. Maybe a disproportionate share of the ground balls they get found holes.

For example, Barry Zito – a pretty bad pitcher – only had 6.8% of his fly balls leave the park last year whereas only 10 qualifying starters had a greater % of their fly balls leave the park than Roy Oswalt (same link as above)– a very good pitcher. If you just look at their respective ERAs – Oswalt was at 3.54 last year and Zito was at 5.15 – well, you still get that one guy’s pretty good and the other guy stinks. However, how high would Zito’s ERA have been if he had had the misfortune of having a similar % of his fly balls leave the park as Oswalt? Oswalt turned 31 last season and had the highest ERA of his career. Is he slippping due to age or was he a victim of bad luck? tRA hopes to tell us.

Ok, so tRA tells us truly how they pitched last year. Statcorner has also regressed tRA to league average and created tRA* which is designed to be the best predictor of a pitcher’s future performance – a handy tool for anyone trying to figure out how well (or poorly) their favorite team’s pitchers will pitch next year.

Finally, Sky has graciously taken all baseball’s SP tRA data and made an adjustment for the fact that NL pitchers didn’t have to face a DH and created a spreadsheet to tell us each SP’s runs above replacement for ’08. You can view or download the spreadsheet here. My contribution to this endeavor is limited to showing you the Cards’ SP’s data for last year. Remember, the tRA* is designed to be a predictor of future performance.

Wainwright 4.19 4.51 23
Wellemeyer 5.10 4.97 16
Lohse 4.99 4.94 19
Looper 5.18 4.87 15
Pineiro 6.14 5.24 -3

20 RAR is considered roughly league-average so we’ve got 1 above league-average pitcher and 2 others right around or slightly below league-average pitchers. Pineiro’s a $7.5 M replacement-level pitcher and Looper’s, of course, a free agent. Follow the "team pivot" at the bottom of the spreadsheet to see that the Cards’ starters last year were 24th in the big leagues. Those who think that our pitching problems last year were limited to the bullpen are sorely mistaken. We’ve got rotation problems as well.

Here are the numbers for this year’s free agent SP crop. I’m including those who’ve already signed.

Sabathia 3.54/2.38 3.87/3.15 81
Sheets 3.45 4.19 50
Lowe 3.24 3.66 57
Burnett 3.69 4.05 59
Johnson 3.32 3.83 51
Ol. Perez 4.98 5.09 18
Wolf 5.46/3.96 5.12/4.67 20
Pettitte 4.50 4.46 37
Garland 5.74 5.22 10
D. Cabrera 6.58 5.78 -6
Moyer 4.89 5.08 20

(Note: I left Sabathia’s and Wolf’s tRA and tRA* stats separate for their two teams b/c I didn’t feel I could combine them accurately).

Cabrera was non-tendered, along w/ Tim Redding, Chuck James, and Chris Capuano. I didn’t include those 3 but thought that Cabrera might be interesting enough to include but there’s not a lot interesting about those numbers. Is there any doubt that Sabathia was the best free agent starter on the market? Is there any doubt that there’s an upper-class of free agent starters and a lower-class of free agent starters? Nothing in that lower class is of any interest to me. If any of it interested Mo, he should have offered Looper arbitration since he’s the same pitcher as some of those other guys and if Looper had accepted, we’d have gotten him for a 1 year deal. Garland’s the one who’s scared me for some time and scares me more now. He’s simply poor and I fear that the fact that he’s thrown over 190 IP 7 years in a row and has won 12+ games 6 times (and 18 twice) will fool the front office into thinking he’s a good pitcher. We already gave a guy like that $10M per year for 4 years. We don’t need another one.

For all those saying RJ’s too old – for 1 year, I’ll take my chances. He’s much better than people like Wolf (and much more likely to pitch 160+ innings, too) or Perez. It’s simply not close. A young, cost-controlled pitcher is still preferred but, lacking our ability to acquire a good, young pitcher, we ought to … well, I’ve said my bit.