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Here’s how the Brewers pitching staff looks when ranked by Average Runs Prevented. For additional context, each pitcher’s Games, Games Started, and Innings Pitched statistics are included.

Stats: 

Average Runs Prevented is the average of park-adjusted, league-adjusted estimates of a pitcher’s actual runs allowed compared to their expected runs allowed.

DRA Runs Prevented is the difference between a pitcher’s expected runs allowed and their DRA performance. 

Direction is the “Direction of Change” between a pitcher’s 2018 Average Runs Prevented and 2018 DRA Runs Prevented.

G is “Games” (total appearances); GS is “Games Started” (total starts); IP is “Innings Pitched.”

Why is this important? DRA is a pitching statistic that estimates each pitcher’s performance based on numerous contextual factors. DRA is a statistic that can describe a player’s performance on the field by correlating Runs Allowed per 9 IP (RA9) to DRA; it is modeled to consistently assess a player’s performance year-to-year; and it is modeled to predict next year’s RA9. Runs Prevented, on the other hand, is a purely descriptive statistic, simply aiming to measure the extent to which a pitcher compares to their park and league environments.

Before we get into the extended analysis, if you’d like to know why this topic is important, consider the following questions; for fun, the exercise could also end here, as there’s a lot to think about with this staff.

….which of these pitchers would you expect to improve in 2019?

….which of these pitchers would you expect to improve in 2019?

….which of these pitchers would you expect to improve in 2019?

By describing Runs Prevented and DRA Runs Prevented statistics year-over-year, it is possible to understand the absolute volatility of pitching performance. DRA is also potentially a tool that can be used to set someone in the right direction for analyzing statistical profiles in order to project improvement or decline.

Let’s take a look at MLB pitchers that worked in 2017 and 2018:

The value of using a statistic such as DRA is that the year-to-year Runs Prevented performance by MLB pitchers is absurdly volatile. The table above demonstrates the absolute value of change in several key statistics for pitchers that worked in both 2017 and 2018. 639 MLB pitchers worked in both 2017 and 2018 seasons. On the whole, this group was quite volatile, with the average change in runs prevented moving by nine runs prevented (positive or negative); a pitcher that worked in both 2017 and 2018 also saw their innings pitched total fluctuate between 33 and 34 innings, and their average games started fluctuate by four. Focusing specifically on starters (i.e., pitchers who started a game in 2017 and pitchers who started a game in 2018), the fluctuations are even wider.

These fluctuations would be the equivalent of Jhoulys Chacin becoming a slightly below average, slightly smaller workload pitcher in 2018, or improving steadily into “ace” territory; Freddy Peralta expanding into a more regular rotation role, or stepping back into a smaller replacement role; Corey Knebel fluctuating to a below average reliever or recovering his excellent high leverage form; or Josh Hader becoming “just” an average reliever or taking the next step in his high leverage ace development. These are just a few examples of the real impact that typical run prevention fluctuations can cause to a team. Each of these pitchers are likely to remain under Brewers contractual control in 2019, so it matters how their performances change.

Let’s dig deeper into that group of 639 pitchers that worked in both 2017 and 2018 to assess the descriptive value of DRA and Runs Prevented. A couple of caveats are in order. First, this is a biased analysis, insofar as I am expressly limiting my search to players that worked in both 2017 and 2018, which excludes a “true talent assessment” of players that missed either of those seasons for a multitude of reasons (from player development, such as Freddy Peralta, to injury, such as Jimmy Nelson). Second, since I will be describing the general direction of DRA, I am not using statistical methods to assess the significance of DRA’s predictions. With these caveats in mind, I think it remains useful to see how DRA assesses players within a single season, and across two seasons.

Now that we’ve discussed the average absolute value of Runs Prevented change between 2017 and 2018, let’s take an overview of this group of pitchers in terms of improvement or decline. Excluding pitchers with Runs Prevented totals between -2 and 2 in 2017 and 2018, which represents a relatively minimal range of fluctuation that could simply be explained by park factors or league environment, more pitchers declined than improved between 2017 and 2018. In many cases, these changes were quite major, as 132 pitchers declined by 10 or more Runs Prevented, while 53 pitchers improved by 10 or more Runs Prevented. The overall magnitude of major declining performances ensured that this group of 639 pitchers was -439 Runs Prevented (!!!) between 2017 or 2018; this means that if each 2017 team retained these pitchers, on average they would have been expected to lose approximately 44 more games (as a group) in 2018, all else held equal.

Based on 2017 performance, could anyone have predicted these directions of change among these pitchers? Once I assembled an Average Runs Prevented analysis of the 2017 MLB season, and isolated pitchers that worked in both 2017 and 2018, I analyzed several aspects of each player’s performance:

• I analyzed the 2017 Direction of Change, which is the change between 2017 Runs Prevented and 2017 DRA Runs Prevented, in order to assess whether a player overperformed or underperformed their DRA.

• I analyzed the 2017 Direction of Change and the difference between 2018 Runs Prevented and 2017 Runs Prevented, in order to assess whether a player’s between-seasons change (2017 to 2018) matched their 2017 underperformance or overperformance. Focusing on 2017 Direction of Change and between-seasons change is one way to describe the types of projections made by DRA.

• I assessed 2017 DRA Runs Prevented and 2018 DRA Runs Prevented in order to determine whether the statistic consistently estimated a pitcher’s contextual performance.

First and foremost, in terms of 2017 and 2018 consistency, DRA consistently assessed 389 pitchers as either Above Average or Below Average in both 2017 and 2018. Since the “Other Pitchers” group is quite a set of outliers, I provided a couple of key statistics about their DRA Runs Prevented.

In this case, the “Other” group is comprised of outliers, including pitchers like Wade Miley and Chase Anderson, as well as Lucas Giolito, Kyle Freeland, and Derek Holland, among others. This is an area where the biased selection of this group of pitchers could impact analysis, as developments such as a new pitch (by Miley) or backed-up stuff and command (by Giolito) create role discrepancies that would be difficult to predict without granular scouting information. Of course, these are precisely the types of uneven player development facts that teams attempt to exploit. Wade Miley was not a particularly good pitcher in 2018, indeed he could have reasonably been replaced (which is partially why he was available for a minor league contract entering 2018); his development to an average pitcher was worth 44 DRA Runs Prevented between 2017 and 2018, a massive improvement that is going to skew nearly any sample of players.

On the whole, it is worth noting that DRA Runs Prevented tracked better than Average Runs Prevented, in terms of absolute value of change, between 2017 and 2018. Among pitchers that worked in both seasons, DRA Runs Prevented fluctuated by approximately 8 runs, compared to approximately 9 runs by Average Runs Prevented. Not bad!

How does DRA work with this group of pitchers in terms of predicting the general direction of change between 2017 and 2018? Based on a pitcher’s internal 2017 difference between DRA and Runs Prevented, that pitcher’s typical improvement or decline between 2017 or 2018 matched the overperformance or underperformance (in terms of 2017 DRA versus 2017 Runs Prevented). DRA correctly assessed a pitcher’s expected performance change in 79 percent of cases:

Within this group of pitchers, DRA performs quite well in terms of assessing the actual size of the Runs Prevented change, as well as the direction. Once I categorized pitchers into groups of players that had Predicted Improvement, Predicted Decline, or some Other Prediction, I compared the change between 2017 and 2018 DRA Runs Prevented to 2017 and 2018 Actual Runs Prevented:

It should be underscored that this is a descriptive account of DRA’s predictions, rather that a statistical test of the significance of DRA’s predictions. Still, what is incredibly impressive about DRA is just how strong the statistic is in anticipating the shape of the run environment, and understanding the wide variance that can occur year over year.

What is interesting is that, according to DRA, the Brewers pitching staff was indeed better than average in 2018. However, there are 22 pitchers from that staff that might reasonably be expected to post a notable improvement or decline in 2019, if one assesses the extent to which they outperformed or underperformed their 2018 DRA. Thus, it is worth repeating the questions about who might be expected to improve in 2019, for even if the overall direction of the club’s pitchers may be expected to stay the course, their shape and distribution of Runs Prevented can all but expected to look quite different.

Josh Hader’s historic success and Jeremy Jeffress’ Comeback-Player-of-the-Year-worthy, All-Star season are certainly worthy of a lot of attention. Corey Knebel’s dominance after his “re-set” in Arizona have made the bullpen even more formidable in September. And David Stearns’ raid of the White Sox reliever pantry has added much needed depth and versatility to what was already a leading bullpen in all of baseball.

But overlooked in this dominance has been Brandon Woodruff. The young righty might just be ready for an October prime-time role in the bullpen, however the Brewers need to deploy him.

Woodruff has pitched just over 40 innings at the big-league level this year, and through September 25 sits in fourth place in Deserved Run Average for all Brewer pitchers who have thrown that many innings.  While good, that statistic actually underrates a bit how good Woodruff has been in the bullpen.

Woodruff made 4 starts this season, mostly in a swingman-type role that shuttled him between the bullpen and starting early in the year before going back down to Triple-A. In those four starts, Woodruff gave up 11 runs in 15.1 innings pitched for a 6.46 ERA. It’s not any surprise that he has done better in relief appearances, as you would expect most starters to be able to do, but the difference has been pretty striking. In his 24.7 relief innings, Woodruff has allowed just 6 runs, good for a 2.19 ERA.

That ERA would trail only Jeremy Jeffress on the team. That ERA is better than Hader, Knebel, or anyone.

It’s backed up by strong peripherals, too. In Woodruff’s relief appearances, he’s striking out better than a batter per inning, but his real strength lies in his ability to get ground balls. On the season, he has approximately 53 percent ground ball rate, which would place him in the top 10 percent of all pitchers in baseball. Those two outcomes might make him the Brewers’ best option with a runner on base in a high-leverage situation late in the game with the team’s better defensive unit behind him.

Much has also been made about the workload of Brewer pitchers, especially as it relates to Josh Hader’s ability to go multiple days in a row and monitoring his total inning count. Brandon Woodrfuff presents a nice relief option to fill in on those days, as he still hasn’t matched last season’s innings total of 120 innings. And he’s been particularly good in multiple-inning outings against Washington (4 IP, 5 K, 0 ER) and the Reds (3 IP, 2 K, 0 ER) since his September call-up.

Woodruff seems fresh, too. His average four-seam fastball velocity is at a season-high 96.8 mph this month, and he’s getting more whiffs on that pitch than at any other time this season in the bigs.

Perhaps more valuable to Craig Counsell is Woodruff’s splits between left and right-handers evening out. Our secret relief ace thus far in his career has had pretty terrible luck against left-handers, including a .377 batting average in balls in play against (.221 BABIP against righties), and a lower career fielding independent pitching against left-handed batters (3.77) than right-handers (4.31). This season however, tells a different story.

Woodruff has performed a little better overall against right-handed batters, which is to be expected, but the numbers are actually pretty close across the board and he’s struck out more left-handers in fewer plate appearances. Even chalking some of this up to a limited sample size this season, these splits are much closer to his career Fielding Independent Pitching stats than his Batting Average on Balls In Play-fueled results against left-handers.

In sum, the Brewers have a fresh reliever who shouldn’t have much of an innings cap, if any, throwing as hard and more effectively than he has at any time this year without an extreme platoon split. Considering Woodruff as a reliever only, he’s been one of the most productive members of a deep and effective bullpen.

Those traits could provide a lot of versatility, should the Brewers choose to employ it.

Woodruff could fill a 2-inning relief role when Hader isn’t available, since he’s not even at his 2017 innings count, and on account of his platoon-busting. For those reasons he might also make either an excellent “opener,” or a bridge from a third or fourth starter to go one time through the order and then to a rested bullpen. His worm-burning tendencies combined with a decent strikeout rate would also be a good option for mid-inning high-leverage situations with runners on base.

But based on how well Woodruff has pitched so far out of the bullpen right alongside the other relief aces for the Brewers this season it would be hard to argue against using him in almost any situation.

Related:
Depth Beats Attrition
Trust the Rotation
Aces Do Not Exist
How to Turn One Hader into Two and a Half Chris Sales

Teams are eager to rely on their bullpens more frequently, and at 5.18 IP/GS for his starters, manager Craig Counsell is about as eager as anyone to turn away from the third time through the order as a starter.

If you’re new to baseball analytics, one of the best possible strategies to learn is the starting pitcher’s “times facing a batting order.” The table above demonstrates On-Base-Percentage plus Slugging-Percentage each time through the order for National League starting pitchers. This may seem like a trivial aspect of the game, but if you read the new midseason scouting reports emerging on your favorite arms, or even look into 2018 MLB Draft scouting reports, chances are you’ll see a line like “without a third pitch, a role in the bullpen could be most likely.” What you’re reading, in nearly any variation of this line, is the strategic idea that in order to beat MLB batters a third time through the order, a starting pitcher is going to need additional pitches to cross-up batters and make adjustments as the game deepens. Milwaukee left-hander Warren Spahn is classically attributed with the quote, “pitchers need two pitches, one they’re looking for and one to cross them up,” but even here Spahn was not quite right; a pitcher needs as many pitches as are necessary to adjust to their designated role. I imagine that if you’re Warren Spahn (perhaps much like Ben Sheets or Clayton Kershaw), life is rather easy with mostly two pitches; if you’re Dave Bush or Victor Santos or Zach Davies or pretty much anyone of the other 300+ starters that work in the MLB, life with only two pitches would probably be miserable.

But perhaps the stats speak on their own: last year, the average NL batter the first time through the order was Cory Spangenberg. By the third time through the order, the average NL batter was Christian Yelich. In order to keep batters closer to the Cory Spangenberg level of production, having command of that third pitch (with a quality “stuff” grade, too) will get the scouts ready to slap that “#3 SP” Overall Future Potential grade.

Manager Craig Counsell was handed a group of supposedly below average-to-horrendous starting pitchers according to most Brewers fans, but as most fans could have surmised from the 2017 squad, pitching was the strength of the organization. And indeed, pitching has continued to serve as the strength of the 2018 club, although statistics like Deserved Run Average suggest that the club may be due for some regression to the mean (in terms of preventing runs). But what was most important about the 2017-2018 offseason was that GM David Stearns built a pitching system, and Counsell’s eagerness to pull starters at just the right time has indeed reflected a machine-oriented approach to pitching. Setting aside the injured Zach Davies and the mechanics-ironing Chase Anderson, the 2018 Brewers starting rotation is lead by Chacin (4 Runs Prevented in 69.0 IP), Brent Suter (2 Runs Prevented in 63.3 IP), and Junior Guerra (approximately 9 Runs Prevented in 60.3 IP after Tuesday night). Counsell has pulled these pitchers early almost uniformly; the Table below compares each pitcher’s last major workload as a starting pitcher to their 2018 workload, in terms of facing a batting order multiple times:

This is what managing with an elite bullpen can do for someone: pretty much every night of the week, Counsell can give each starting pitcher the same workload. In contrast to the narrative of burned out bullpens, which Kyle Lesniewski has also studied at Brew Crew Ball, it is worth arguing that Counsell is providing starting pitchers with a clearer definition of a workload. In fact, the old saying for starting pitchers to “go as deep as you can into the game” is rather problematic; if your stuff isn’t there, you’re probably done after 100 pitches and five (or fewer innings), which will be offset by the great 7.0-to-8.0 IP evenings, or complete games. Counsell and the Brewers are almost giving their starting pitchers better role certainty than any “traditional” starting pitcher has ever had (at least in the last 30 years): “give me your best 16 outs.” This is how you turn Guerra, Chacin, and Suter in a 15 Runs Prevented machine, which is one hell of a low rotation, by the way, and exactly the type of performance that turns a low rotation into an entity that offsets the lack of a so-called “Ace” at the top.

Has it worked? The Table below demonstrates that while there are some hiccups along the way, this Big Three low rotation has indeed improved in at least one area of the game, and in some cases the third time through the batting order is receiving grand benefits. These stats are even before Guerra’s course correction at Cleveland:

What is notable about minimizing a pitcher’s times through the batting order is that they can theoretically readjust their plan of attack. Someone like Guerra or Chacin no longer has to think about establishing his best stuff and figuring out what he’s going to do 100 pitches later; Suter might not ever have been expected to go that deep into ballgames, but even the Raptor-esque southpaw can arguably find some benefit in his ballgame by understanding that he needs to go 16 outs. Looking through Brooks Baseball pitching logs, it is arguably the case that what Counsell (and presumably Stearns, coaching staff, and the Front Office in this case) is doing is indeed turning each of these guys into….let’s call them “really, really long relievers who start the game”:

• According to Brooks Baseball, compared to his full season in 2016, Junior Guerra cut his splitter and slider usage (both below 15 percent!) while increasing his secondary running fastball (which Guerra selected approximately 23 percent of the time entering Tuesday night). As a result, Guerra is getting more whiffs on both of his fastballs as a group, and improving his slider whiffs without yielding too much value from his splitter. He’s also improving his pop-ups, suggesting batters are getting weak contact even though they are facing his fastball more frequently (presumably making Guerra more “predictable”).

• As covered by Andrew Salzman in the latest Weekend Recap at BPMilwaukee, Brent Suter is becoming a fastballl-first pitcher. The southpaw is firing what appears to be a near-cutting, rising fastball (think Jacob Barnes) two-thirds of his offerings, with good results in terms of improving swings-and-misses.

• By contrast, Chacin is much more of his previous self, with the caveat that he’s working his slider slightly more frequently than in 2017 while moving away from his primary fastball a bit. His outcomes with these pitches are rather similar as well, which suggests that even if the Brewers are deploying Chacin in a manner that is more systematic and potentially more radical, he is not deviating from what got him through a very successful 2017 campaign, earning him his excellent contract.

Milwaukee is receiving much deserved praise for their bullpen, which was expertly curated by David Stearns during his first two seasons with the club. Now the rewards are visible during what could become one of the most important seasons in franchise history, returning the club to their first extending contending window in quite some time. But it is worth emphasizing that Stearns was correct in assembling a starting pitching staff that could complement the relief staff, and together with the efficient fielders, the arms are a Runs Prevented machine. None of these moves were terribly difficult to make, either, which means that the most thrilling part of this series of moves is that they can be repeated in future seasons: Junior Guerra was Stearns’s very first acquisition, Brent Suter was a deep draft pick during the Doug Melvin era that was freed into a stunning big league role, and Jhoulys Chacin was a proven veteran signed off the margins of an underwhelming free agency class that nevertheless yielded some surprising contracts elsewhere. This is what systematic baseball can look like in Milwaukee, and it involves neither being “cheap” (Chacin signed a decent guaranteed deal) nor “dogmatic” about acquisition style (waivers, free agency, and draft are represented here). Most importantly for the prospect arms, both hyped (Corbin Burnes and Luis Ortiz) and unassuming (Freddy Peralta and others), the Brewers front office is gleefully demonstrated that nobody needs aces any longer. Bring your two best pitches for 16 outs, and let’s get on with it!

Photo Credit: David Richard, USA Today Sports Images

Resources:
Baseball Reference. Player Pitching Splits, NL Pitching Splits, 2016-2018 [CSV].