Poll 2019: Which Group of Pitchers Performs Better?

Since 2013, I have polled you dashingly attractive readers on which group of pitchers you think will post the better aggregate ERA post all-star break. The two groups were determined based on ERA-SIERA disparity, pitting the overperformers versus the underperformers during the pre-all-star break period.

I came up with this idea given my faith in using SIERA over smaller samples, rather than ERA, as I generally ignore ERA completely as late as the middle of the season and it’s interesting to learn how everyone else thinks. Will the SIERA overperformers continue to outperform, perhaps due to continued strong defensive support and/or more pitcher friendly ballparks, or will the magic vanish? And is it just bad luck that is due to reverse course for the SIERA underperformers or are they being hampered by one of the aforementioned factors that should continue to play a role the rest of the way?

My initial population group consisted of 110 pitchers who have thrown at least 70 innings, which included some that are no longer in a rotation and/or are injured (I excluded these pitchers from making the tables). Group A is composed of the 10 largest SIERA overperformers, while Group B is composed of the 10 largest SIERA underperformers.

Group A – The SIERA Outperformers
Name K% BB% LD% GB% FB% IFFB% BABIP LOB% HR/FB ERA SIERA Diff
Zach Davies 15.4% 7.3% 24.7% 41.1% 34.2% 6.7% 0.303 79.4% 10.6% 3.09 5.27 -2.18
John Means 20.6% 6.6% 15.4% 37.2% 47.4% 8.1% 0.252 81.1% 8.1% 2.52 4.67 -2.15
Luis Castillo 28.8% 12.3% 16.3% 56.3% 27.5% 4.5% 0.224 83.2% 13.6% 2.29 4.22 -1.93
Mike Minor 24.2% 8.7% 17.9% 43.3% 38.8% 10.9% 0.264 86.5% 10.1% 2.54 4.41 -1.87
Hyun-Jin Ryu 23.7% 2.4% 23.5% 50.7% 25.8% 7.7% 0.266 87.2% 12.8% 1.73 3.49 -1.76
Sandy Alcantara 16.1% 10.8% 20.3% 46.1% 33.7% 10.7% 0.281 72.7% 9.7% 3.83 5.57 -1.74
Mike Soroka 20.1% 5.8% 21.9% 57.0% 21.1% 14.8% 0.266 76.5% 7.4% 2.42 4.02 -1.60
Brett Anderson 12.0% 7.6% 20.5% 53.1% 26.4% 8.9% 0.268 74.0% 11.1% 3.87 5.34 -1.47
Julio Teheran 20.7% 11.6% 21.6% 40.6% 37.8% 7.5% 0.270 77.2% 10.3% 3.77 5.20 -1.43
Mike Fiers 16.0% 6.9% 19.8% 38.3% 42.0% 15.4% 0.232 74.0% 11.0% 3.87 5.25 -1.38
Group Average 19.8% 8.1% 20.3% 46.3% 33.4% 9.7% 0.263 79.3% 10.4% 2.99 4.74 -1.74
Lg Avg (All Starters) 22.8% 8.5% 21.4% 42.9% 35.6% 9.8% 0.295 72.2% 15.1% 4.48 4.38 0.10

Group B – The SIERA Underperformers
Name K% BB% LD% GB% FB% IFFB% BABIP LOB% HR/FB ERA SIERA Diff
Blake Snell 32.8% 8.3% 25.5% 41.2% 33.3% 9.7% 0.351 68.8% 18.1% 4.70 3.45 1.25
Reynaldo Lopez 19.5% 8.6% 19.9% 33.0% 47.1% 16.3% 0.325 67.8% 15.6% 6.34 5.12 1.22
Matt Strahm 22.4% 4.9% 22.6% 33.1% 44.4% 7.5% 0.301 72.8% 17.9% 5.45 4.32 1.13
Chris Sale 34.5% 5.9% 19.1% 43.0% 37.8% 9.5% 0.307 69.5% 16.8% 4.04 3.03 1.01
Chris Archer 25.3% 11.8% 22.5% 37.3% 40.2% 8.3% 0.279 75.6% 23.8% 5.52 4.71 0.81
Felix Pena 25.2% 8.2% 22.1% 39.7% 38.2% 5.1% 0.262 70.7% 19.2% 4.74 3.97 0.77
Zack Wheeler 25.6% 6.7% 20.9% 44.5% 34.6% 12.9% 0.313 65.9% 13.8% 4.69 3.98 0.71
Matthew Boyd 32.0% 4.5% 20.7% 36.5% 42.9% 10.5% 0.314 78.3% 16.7% 3.87 3.17 0.70
Jakob Junis 20.8% 8.1% 20.4% 45.1% 34.5% 6.2% 0.311 68.9% 17.7% 5.34 4.67 0.67
German Marquez 23.5% 5.3% 20.7% 51.5% 27.8% 4.9% 0.310 68.5% 16.7% 4.46 3.86 0.60
Group Average 26.1% 7.1% 21.2% 41.1% 37.7% 9.5% 0.309 70.4% 17.3% 4.87 4.00 0.87
Lg Avg (All Starters) 22.8% 8.5% 21.4% 42.9% 35.6% 9.8% 0.295 72.2% 15.1% 4.48 4.38 0.10

Group Averages Comparison
Group Avg K% BB% LD% GB% FB% IFFB% BABIP LOB% HR/FB ERA SIERA Diff
A 19.8% 8.1% 20.3% 46.3% 33.4% 9.7% 0.263 79.3% 10.4% 2.99 4.74 -1.74
B 26.1% 7.1% 21.2% 41.1% 37.7% 9.5% 0.309 70.4% 17.3% 4.87 4.00 0.87

Unlike in some previous years, these are wildly different groups. Group B (the underperformers) has posted a significantly higher strikeout rate than Group A (the overperformers), while also walking a lower percentage of batters. However, Group A has induced a higher rate of grounders, which is important in a time with a historically high rate of homers per fly ball. The groups have posted nearly identical IFFB% marks.

Not surprisingly, massive differences exist in the three luck metrics — BABIP, LOB%, and HR/FB rate. Even though grounders go for hits more often than flies, Group A has allowed a well below league average BABIP. They did post a lower line drive rate, but only marginally, and not nearly enough to explain the BABIP discrepancy. Group A has also had a much easier time stranding baserunners, or enjoyed better bullpen support if they left runners on when departing the game. Lastly, Group B has been crushed by this insane power surge, while Group A is thinking, “what surge?”.

Overall, SIERA suggests that Group B represents a significantly better mix of pitchers than A, yet their ERAs tell the opposite story. Which group performs better over the rest of the season? Let’s get to the poll questions. Feel free to share your poll answers and why you voted the way you did.


 

 

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Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year. He produces player projections using his own forecasting system and is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. Follow Mike on Twitter @MikePodhorzer and contact him via email.

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couthcommander
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couthcommander

Outside of SIERA, it looks like group B has a more favorable strength of schedule. This probably won’t even be close.