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.
| 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 |
| 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 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.
Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year and three-time Tout Wars champion. He is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. Follow Mike on X@MikePodhorzer and contact him via email.
Outside of SIERA, it looks like group B has a more favorable strength of schedule. This probably won’t even be close.