The below table displays the 15 pitchers who outperformed their SIERA the most in May. As we can see, looking at this kind of data can bring us all different kinds of hurlers with various styles.
| Rank | Player | K% | BB% | HR/9 | BABIP | LOB% | ERA | SIERA | Diff |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Andrew Cashner | 10.1% | 9.4% | 0.49 | .250 | 76.9% | 2.92 | 5.58 | -2.66 |
| 2 | Ervin Santana | 18.0% | 11.4% | 1.29 | .153 | 86.7% | 2.57 | 5.11 | -2.54 |
| 3 | Jason Vargas | 15.8% | 8.9% | 1.04 | .267 | 84.2% | 3.12 | 5.52 | -2.40 |
| 4 | Adam Wainwright | 17.2% | 10.9% | 0.29 | .278 | 80.8% | 2.64 | 4.96 | -2.32 |
| 5 | Lance McCullers | 26.2% | 7.1% | 0.50 | .213 | 89.7% | 0.99 | 2.93 | -1.94 |
| 6 | Derek Holland | 22.0% | 9.9% | 1.42 | .286 | 80.6% | 2.56 | 4.40 | -1.84 |
| 7 | JC Ramirez | 12.1% | 3.8% | 1.34 | .276 | 87.9% | 2.67 | 4.49 | -1.82 |
| 8 | German Marquez | 19.4% | 7.8% | 1.17 | .258 | 89.5% | 2.64 | 4.45 | -1.81 |
| 9 | Alex Cobb | 17.2% | 8.6% | 0.68 | .243 | 77.6% | 2.95 | 4.66 | -1.71 |
| 10 | Michael Fulmer | 18.3% | 3.9% | 0.00 | .322 | 75.6% | 2.19 | 3.87 | -1.68 |
| 11 | Carlos Martinez | 24.6% | 7.8% | 0.81 | .202 | 83.8% | 2.03 | 3.65 | -1.62 |
| 12 | Jaime Garcia | 17.2% | 10.5% | 0.55 | .242 | 74.6% | 2.45 | 4.07 | -1.62 |
| 13 | Yu Darvish | 23.3% | 9.8% | 1.45 | .268 | 91.4% | 2.90 | 4.25 | -1.35 |
| 14 | Jake Odorizzi | 23.1% | 7.7% | 1.51 | .237 | 88.2% | 2.78 | 4.05 | -1.27 |
| 15 | Dylan Bundy | 16.1% | 8.6% | 1.38 | .263 | 80.3% | 3.92 | 5.15 | -1.23 |
The Ticking Time Bomb
Exactly how long can Andrew Cashner go before reality catches up to him? This question follows him every time the right-hander takes the mound for the Texas Rangers.
It seemed like only a matter of time once he allowed 5 runs on 6 hits and 4 walks in just 5 innings to the Boston Red Sox on May 23rd. That is, until he turned around for his next turn in the rotation and pieced together 7 innings of 1-run ball against the Toronto Blue Jays, who were one of baseball's best offenses in May.
Even if you want to ride this wave, it's really hard to trust a pitcher who is walking more hitters (12.5%) than he's striking out (10.7%) and has produced a low BABIP (.250) despite allowing more contact than ever before (85.1%) -- even if the quality of contact has improved -- with a fastball that continues to dip in velocity.
The One to Not Worry About
On more than a few occasions, we'll stumble upon hurlers outperforming their peripherals by a significant margin, but even if their ERA was on par with their SIERA, it'd still be quite tasty. Lance McCullers falls into that category.
While his BABIP and strand rate (LOB%) are both elevated compared to his season-long stats (.272 and 82.3%, respectively), he's pairing quite nicely with Dallas Keuchel at the top of the Houston Astros' starting rotation. And when it comes to what McCullers needed to work on to take his game to the next level, he's done it so far this season.
Now, all he has to do is stay healthy and get 30 starts under his belt so we have an idea of just how good he can be.
Deja Vu All Over Again
When we went through this exercise at the end of April, there were a number of hurlers due for some regression. We already touched on Jeremy Hellickson, but Ervin Santana also fell into that category. He had the second-biggest difference between his ERA and SIERA, and his fast start was engineered by an incredible .129 BABIP allowed, along with a 99.0% strand rate.
Sustaining those numbers throughout the course of a season -- and without being a big-time swing-and-miss pitcher -- isn't possible, and he wasn't able to duplicate those numbers in May. All he did, though, was allow a .153 BABIP and 86.7% strand rate while watching his strikeout rate and walk rate go in opposite directions.
This still feels a bit unsustainable, but the crafty veteran certainly enjoys having a defense behind him that currently ranks second in baseball with regard to defensive runs saved (29) and and Ultimate Zone Rating (18.1) this season.