Hey Man, I’m Concerned About Your Walk Rate
This season, Blake Snell has the highest walk rate among qualified starters at 13.4%. The league average mark among starters is 7.9%. Yet, Snell has a very solid 2.61 ERA (3.89 xERA) and is allowing only a .197 batting average against his opponents this season. His 1.27 WHIP is actually below the league average (1.31) because of how well he is limiting hits. This is not a new thing for Blake Snell. He has run up his BB% to an even higher peak before:
In 2021, Snell finished the year with a 4.20 ERA (4.82 xERA) and just a .211 batting average against. Let’s bring his ERA into the same chart to see how his BB% and ERA relate to each other:
By rolling statistics, never has his BB% and ERA been so far apart. Snell is having a good year. Don’t get me wrong. Michael Baumann summed it up perfectly in mid-July when he wrote:
Snell is a man of contrasts. Among 66 qualified starters in 2023, he has the worst walk rate but the third-best strikeout rate. He’s allowed more walks than any pitcher in the National League this season, but he’s also allowing the fewest hits per nine innings.
If you’re rostering him on your fantasy team and just rolling him out every single start, you’re walking a fine line. On average, starters leave 72% of runners on base. Snell’s LOB% in 2023 is at 85.9%. That is not a career-high. He recorded an 88% LOB% in 2018 with the Rays and the year he won the Cy Young Award.
I begin with Snell as a case study of pitchers who are producing and making your fantasy team better, yet are teetering on the edge and have indicated some serious risk of throwing up a stinker. If you are winning your ERA or WHIP category by a small margin, you may want to pay close attention to the following starting pitchers:
| Name | IP | BB% | AVG | WHIP | BABIP | LOB% | ERA | xERA | FIP | xFIP | SIERA | Stuff+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Blake Snell | 119.0 | 13.6% | 0.197 | 1.29 | 0.280 | 86.0% | 2.50 | 3.85 | 3.62 | 3.60 | 4.09 | 108 |
| Josiah Gray | 122.0 | 10.7% | 0.251 | 1.43 | 0.294 | 81.3% | 3.54 | 4.49 | 4.72 | 4.97 | 5.00 | 88 |
| Charlie Morton | 119.1 | 10.3% | 0.252 | 1.42 | 0.322 | 78.7% | 3.62 | 4.83 | 4.08 | 4.09 | 4.31 | 108 |
| Shohei Ohtani | 120.2 | 10.2% | 0.185 | 1.07 | 0.241 | 79.3% | 3.43 | 3.82 | 4.14 | 3.52 | 3.57 | 121 |
| Taijuan Walker | 119.2 | 9.7% | 0.234 | 1.27 | 0.274 | 75.1% | 3.99 | 4.10 | 4.34 | 4.49 | 4.71 | 92 |
| Marcus Stroman | 128.2 | 9.3% | 0.225 | 1.24 | 0.277 | 67.6% | 3.85 | 4.02 | 3.59 | 3.79 | 4.20 | 102 |
| Shane McClanahan | 111.0 | 9.1% | 0.219 | 1.18 | 0.275 | 83.3% | 3.00 | 3.91 | 3.78 | 3.83 | 4.04 | 112 |
| Sonny Gray | 117.1 | 8.9% | 0.235 | 1.27 | 0.308 | 75.0% | 3.22 | 4.02 | 2.93 | 3.83 | 4.21 | 103 |
| Corbin Burnes | 133.1 | 8.5% | 0.193 | 1.05 | 0.235 | 73.0% | 3.44 | 3.29 | 3.89 | 3.91 | 4.05 | 123 |
| Jon Gray | 108.1 | 8.3% | 0.239 | 1.23 | 0.278 | 77.0% | 3.66 | 4.46 | 4.38 | 4.47 | 4.65 | 96 |
| Lucas Giolito | 126.1 | 8.1% | 0.233 | 1.23 | 0.279 | 79.1% | 3.85 | 4.49 | 4.55 | 4.30 | 4.06 | 94 |
Out of the 23 qualified starting pitchers who have a greater than average BB%, 12 of them have an ERA greater than 4.00. That leaves 11 qualified starters from the high walk rate group with a sub-4.00 ERA. Within that group of 11, Snell, Shane McClanahan, and Sonny Gray have the best ERAs. In fact, there are a lot of pitchers above who could finish the year with really high walk rates and really low ERAs. For example, Snell, Ohtani, Burnes (who actually has an xERA lower than his ERA) are suppressing solid contact as they all have batting averages against below .200. They also have some of the best Stuff+ numbers in the group. Alex Chamberlain quoted Tom Tango in one of his ERA estimator pieces as saying:
…if a pitcher has an xERA that is significantly higher than his actual ERA, it should make you want to take a closer look into how he suppressed those runs.
Snell, Ohtani, and Burnes are all great pitchers with great stuff and it doesn’t take the Sherlock Holmes of baseball data to identify that they are able to walk opponents and keep them on base because the guys behind them can’t square anything up. But if we tweak these qualifiers slightly, lowering ERA and increasing walk rate, we see that it’s unusual for pitchers to maintain this imbalance.
In the past two seasons (2021-2022), there have only been two pitchers to have less than a 3.75 ERA and higher than a 9% walk rate. Lance McCullers Jr. did it in 2021 and Dylan Cease did it in 2022. Right now, in 2023, there are eight qualified starters who fall into that category. I think we can safely assume that a few of them will fall out. Take a look at the number of pitchers who have fallen into this category by season’s end since 2010:
So, now that we’ve determined that all these pitchers will not finish in the sub-3.75 category this season, the question is, which ones do we bet on actually finishing under 4.00? In truth, the 4.00 part isn’t really important. What’s important is trying to identify which of these pitchers, who have been coasting in the “automatic start” category, should soon throw up a couple of stinkers. The best way to do that without re-inventing the wheel is to simply look at ROS projections, in this case, I’ll be using THE BAT.
| Name | ERA | ERA_ROS | BB% | BB%_ROS | LOB% | LOB%_ROS | FIP | FIP_ROS |
|---|---|---|---|---|---|---|---|---|
| Blake Snell | 2.50 | 4.08 | 13.6% | 11.0% | 86.0% | 72.3% | 3.62 | 3.88 |
| Shane McClanahan | 3.00 | 3.69 | 9.1% | 7.6% | 83.3% | 73.4% | 3.78 | 3.68 |
| Sonny Gray | 3.22 | 4.13 | 8.9% | 8.6% | 75.0% | 70.2% | 2.93 | 3.95 |
| Shohei Ohtani | 3.43 | 3.47 | 10.2% | 8.6% | 79.3% | 75.3% | 4.14 | 3.65 |
| Corbin Burnes | 3.44 | 3.78 | 8.5% | 7.6% | 73.0% | 72.5% | 3.89 | 3.83 |
| Josiah Gray | 3.54 | 5.24 | 10.7% | 9.9% | 81.3% | 68.5% | 4.72 | 5.52 |
| Charlie Morton | 3.62 | 4.48 | 10.3% | 9.4% | 78.7% | 70.2% | 4.08 | 4.29 |
| Jon Gray | 3.66 | 4.64 | 8.3% | 8.3% | 77.0% | 69.7% | 4.38 | 4.64 |
| Lucas Giolito | 3.85 | 4.45 | 8.1% | 8.3% | 79.1% | 71.1% | 4.55 | 4.45 |
| Marcus Stroman | 3.85 | 4.34 | 9.3% | 7.6% | 67.6% | 69.2% | 3.59 | 4.13 |
| Taijuan Walker | 3.99 | 4.74 | 9.7% | 8.0% | 75.1% | 68.8% | 4.34 | 4.88 |
I’ve highlighted some big differences between what some of these pitchers have done this season and what projection systems expect them to do moving forward. While every single one of these pitchers is expected to have higher ROS ERAs than they currently have displayed, a few of them are expected to rise significantly and the ROS ERAs highlighted in yellow are expected to rise by a full point.
First, Snell’s ERA is expected to rise, and while he is doing such a great job of limiting hits and doing it with solid stuff, walking the high walk rate high line is going to catch up with him. Second, Josiah Gray has been getting lucky and there’s no way around it. All of his expected peripheral stats are higher than his actuals and he has done it without very good stuff. Both Snell and Gray are expected to have big drop-offs in the runners they leave on base, as is Shane McClanahan. Lastly, Sonny Gray doesn’t fall into the full point rise ERA category, but he does fall into the full point rise FIP category. His current 0.31 HR/9 is simply too low to sustain.
Oddly enough, all of these walk rates are expected to go down by ROS with the exception of Lucas Gioltio. What’s up with that? I don’t know. It does appear that Giolito’s walk rate has bounced up and down in the last few seasons, but I suppose THE BAT projects a little less command in the last few months of the season? He’s had four seasons on record above his current mark and only three seasons below. Maybe that’s why?
One last thing to do would be to try to classify these pitchers with the ol’ naked eye test. Here we go:
I’m extra worried: Blake Snell, Josiah Gray, Charlie Morton
There’s some cause for concern: Shane McClanahan, Sonny Gray, Marcus Stroman
It is what it is: Shohei Ohtani, Corbin Burnes, Jon Gray, Lucas Giolito, Taijuan Walker
These pitchers, most of them at least, are great fantasy starters in any format. But the wheels are starting to come off on a few of their performances so far. See the warning signs. They’re all around. There’s no need to drop them, trade them away for nothing, or to bench them for the rest of the season. But these are the pitchers who should be given a little extra attention when deciding whether or not to keep them in your lineup in their next few starts.
Shouldn’t senga be in this too? 110.2 IP, 3.25 era, 11.6% bb rate.