Those fickle pitchers!
by Jeffrey GrossNovember 12, 2010
We all know ERA is largely bunk as a stat (well, maybe not really...), but what is the best metric for measuring a pitcher's true talent and baseline? Is it FIP? xFIP? What about tERA? Or SIERRA (which I think stands for "unnecessarily convoluted statistic which has no greater predictive power")?
Each has their virtues and limitations. FIP, for example, measures a pitcher's three most controllable stats: strikeouts, walks and home runs, attempting to find the context neutral talent line. FIP, of course, ignores the batted ball rates of pitchers, which affects the home run data.
xFIP tries to deal with that problem by adjusting the home run rate, which studies show to be a regression function of flyballs, to a regressed home run rate (11.5 percent). xFIP, however, ignores clearly relevant elements such as park factors and others, primarily infield flyball rates (well, at least the traditional formulation of xFIP as it appears on Fangraphs does). tERA tries to deal with this by looking at a pitcher's batted ball distribution to predict ERA, but that's hardly context neutral and batted ball distributions require larger sample sizes to offer reliability.
Advantages and limitations abound among the most popular metrics. A good fantasy baseball
Irrespective of this scaling differential, however, I have compiled a list of variations among the big three peripheral ERA stats (FIP, xFIP, tERA) for all qualified starting pitchers in 2010 (P_Variance) to give us a look at who the various peripheral stats agree on the most. This, in theory, gives us a list of the "safest" pitchers to forecast; that is, an indexed list of those most likely to perform as expected by any given ERA predictor.
This spreadsheet is intended to help you make better decisions on how to allocate your auction budget on draft day in 2011. For reference, there's also a variance column (T_Variance) which compares the big three peripheral ERA stats to actual ERA.
You can download the UPDATED pre-sorted spreadsheet by clicking here.
First, a sample of the most desirable guys who seemingly fall within the "you know what you are getting" category (sorted by P_Variance):
Name Team ERA FIP xFIP tERA P_Var T_Var Ted Lilly - - - 3.62 4.27 4.16 4.21 0.003033 0.090033 Shaun Marcum Blue Jays 3.64 3.74 3.90 3.77 0.007233 0.011492 Rick Porcello Tigers 4.81 4.29 4.34 4.43 0.005033 0.055492 J. Masterson Indians 4.70 3.93 3.98 3.81 0.007633 0.162433 Trevor Cahill Athletics 2.97 4.19 4.11 4.01 0.008133 0.326533 Roy Oswalt - - - 2.76 3.27 3.45 3.34 0.008233 0.093500 Jon Lester Red Sox 3.25 3.13 3.29 3.30 0.009100 0.006092 Ryan Dempster Cubs 3.96 3.96 3.83 4.04 0.011233 0.007558 C. Carpenter Cardinals 3.22 3.69 3.84 3.62 0.012633 0.070092 Phil Hughes Yankees 4.18 4.24 4.32 4.09 0.013633 0.009425 Ricky Romero Blue Jays 3.77 3.65 3.73 3.88 0.013633 0.009158 Scott Baker Twins 4.49 4.02 4.10 4.25 0.013633 0.042700 Max Scherzer Tigers 3.50 3.71 3.84 3.95 0.014433 0.037400 Carl Pavano Twins 3.81 4.00 3.97 4.20 0.015633 0.025633 Tim Hudson Braves 2.79 4.03 3.84 3.79 0.016033 0.311358 W. Rodriguez Astros 3.60 3.50 3.68 3.77 0.018900 0.013225 Cole Hamels Phillies 3.15 3.67 3.46 3.72 0.019033 0.067133 R.A. Dickey Mets 2.84 3.65 3.88 3.63 0.019300 0.206467 A. Wainwright Cardinals 2.42 2.86 3.14 2.93 0.021233 0.091625 Dan Haren - - - 3.91 3.71 3.67 3.96 0.024700 0.020692 Tim Lincecum Giants 3.43 3.15 3.21 3.46 0.027033 0.024158
The best buy values of this list seem to be Justin Masterson and Scott Baker. The underlying numbers on these two pitchers seem to agree that both are in for much better and quite useful (4.00 ERA or better) fantasy baseball seasons following terrible ERAs in 2010. I doubt either will cost you much in 2011.
In terms of stable values, Shaun Marcum and Jon Lester seem to take the cake. Their ERAs seem to most match their underlying numbers. They will not come cheap, but they will likely not disappoint either.
Guys to avoid (omitted above, see data file) on this list of "you know what you are getting" include Bronson Arroyo, Matt Garza and Wade Davis. They seem the most likely to regress of the bunch.
And then we have a sample of the wild cards:
Name Team ERA FIP xFIP tERA P_Var T_Var Jason Vargas Mariners 3.78 3.95 4.82 3.57 0.410633 0.301533 Anibal Sanchez Marlins 3.48 3.38 4.22 3.38 0.235200 0.164900 Mark Buehrle White Sox 4.28 3.90 4.69 3.88 0.213433 0.146092 Tommy Hanson Braves 3.33 3.31 4.04 3.21 0.205300 0.145892 Jason Hammel Rockies 4.76 3.67 3.80 4.45 0.174633 0.271133 Mat Latos Padres 2.92 3.00 3.36 2.53 0.173233 0.115958 J. Verlander Tigers 3.38 2.95 3.71 3.08 0.165233 0.114600 L. Hernandez Nationals 3.66 3.95 4.76 4.37 0.164100 0.231900 Johan Santana Mets 2.98 3.54 4.32 3.76 0.161733 0.307333 C. Billingsley Dodgers 3.57 3.07 3.81 3.21 0.154533 0.113700 C.Kershaw Dodgers 2.82 3.07 3.74 3.05 0.154233 0.157267 David Price Rays 2.72 3.42 3.99 3.27 0.144300 0.272600 Matt Cain Giants 3.15 3.62 4.18 3.46 0.142933 0.186292 Dallas Braden Athletics 3.50 3.80 4.41 3.74 0.137433 0.150025 Jered Weaver Angels 3.01 3.06 3.51 2.79 0.132300 0.091225 Doug Fister Mariners 4.11 3.65 4.27 3.65 0.128133 0.101467 Cliff Lee - - - 3.18 2.58 3.23 2.65 0.127300 0.117267 James Shields Rays 5.18 4.24 3.72 4.40 0.126400 0.365167 Fausto Carmona Indians 3.77 4.11 4.39 3.70 0.120433 0.102292 Gio Gonzalez Athletics 3.23 3.78 4.18 3.51 0.113633 0.163767 C.J. Wilson Rangers 3.33 3.53 4.16 3.78 0.100633 0.127933 Mike Pelfrey Mets 3.66 3.82 4.46 4.20 0.103600 0.131567 Y. Gallardo Brewers 3.84 3.02 3.42 3.69 0.113633 0.129425 Clay Buchholz Red Sox 2.60 3.65 4.18 3.94 0.070433 0.484758 Derek Lowe Braves 4.00 3.89 3.65 4.20 0.076033 0.052567
The best upside gambles of this list seem to be Tommy Hanson (is he a 3.21 tERA guy or a 4.04 xFIP guy?), Mat Latos (his "downside" is seemingly a solid 3.36 xFIP, but he has only one year in the majors) and David Price (is he a low 3's or low 4's ERA guy?). Kershaw also seems to have a "pure upside" arm if he's truly improved his control.
On the other hand, there are some questionable risks: Anibal Sanchez (is he the 3.38 tERA guy or the 4.22 xFIP guy?), Jason Hammel (the 4.45 tERA guy or the 3.80 xFIP guy?) and Johan Santana, who is already coming off injury. Clay Buchholz's underlying peripherals have changed so much year-to-year that it's hard to peg his true talent too.
And then there are some guys who are just not worth the risk (at least not in my eyes): Fausto Carmona, Doug Fister, C.J. Wilson and Jason Vargas.
As always, leave the love/hate in the comments.
Jeffrey Gross is an attorney (and die-hard Cubs fan) who currently resides in Green Bay, Wisconsin. In addition to writing for The Hardball Times, he also reviews tasty adult beverages as part of a side project titled "saBEERmetrics." He previously worked for The Daily Illini and Northern Star newspapers as a film critic and sportswriter (respectively). You can reach him by email at saBEERmetrics AT gmail DOT com.
<< Return to Article