The Brewers are officially finished with half of their games, providing fans and analysts with a nice theoretical signpost to assess the club. So far so good for the first place Brewers, who are maintaining a tenuous lead over the Pythagorean (Run Differential, Runs Scored / Runs Allowed expected record) superior Cubs in the National League Central and Atlanta in the race for National League playoff positioning. Meanwhile, the Dodgers are surging thanks to a 21-9 stretch, while the Cardinals, Nationals, Phillies, and Pirates are fading at the moment. But there’s a boatload of baseball to be played, and even the distance between the Pirates and Brewers is hardly insurmountable. So, are these Brewers a playoff club?
What is a Playoff Team?
At Baseball Prospectus Milwaukee Twitter (@BPMilwaukee), I keep a daily record of the club’s Pythagorean Record progress. The benefit of keeping a daily record of the club’s progress in Runs Scored and Runs Allowed, scaled to the National League and Miller Park environment, is that one can track the variance of the club over time, and understand trends by creating different time horizons throughout the season. For example, now that the season reached the official halfway point, it is possible to gauge the 2018 Brewers’ midseason success compared to the 2017 club. Below, Table One demonstrates the average of daily run differential records, standard deviation of that average, and the contextual Runs Scored and Runs Allowed after 81 games.
Table One: Midseason 2017 and 2018 Brewers Run Differential Comparison
|Daily Pythagorean Midseason||Average RS / RA||StDev||RS||RA|
The composition of a baseball team includes the “true” talent of pitching, batting, and fielding elements, as well as the distribution of those elements in time, which is why it is important to understand the strength of a team during a fixed point in time and their average and variant performances over time. In this regard, what is difficult about assessing the 2018 Brewers is that although one can understand that the team is indeed better than the 2017 varietal in terms of RS / RA elements, there is notably more variance in the 2018 squad. This variance can be attributed to games six-to-twenty for the 2018 Brewers, as well as games 28-to-44, which are two stretches during which the club respectively experienced terrible (including bottoming out at a 57-win run differential early on) and mediocre baseball. From game number 48 onward, the Brewers have averaged a 90-win run differential, which suggests that the team has indeed corrected numerous elements; but this does not make the elements that caused great variance during the first 48 games any less real (especially in terms of extrapolating trends).
So the 2018 Brewers might indeed be better than the 2017 Brewers, but they are also demonstrating worse “true talent floors” and more variance than the slow-and-steady 2017 club. Choose your poison: no one is going to print “Most Volatile Team” on any 2018 Playoff gear should Milwaukee reach that point.
Over the off season, I used the theory of Daily Pythagorean variance analysis to assess the New Wild Card Era (2012-2017) playoff teams. While this form of analysis can be helpful for assessing a team internally, over the course of 162 games (or even several seasons!), it can also be helpful to demonstrate the various run differential compositions that populate the playoffs. By assessing each playoff team (and midseason contender) according to the average of their daily run differential, it is possible to determine the average traits of playoff teams in the expanded Wild Card format, while also understanding how certain types of outlier teams reach the playoffs.
An additional benefit of keeping average and standard deviation of a uniform number of baseball games (i.e., 81 observations, 162 observations) is that one can use statistical tests such as a Student’s T-Test to determine the statistical significance of differences between teams. The implication of this last point should not be taken to state that one can more realistically predict the odds of one particular team reaching the playoffs, but rather that by assessing teams according to their deviation from their respective means one can provide significant comparisons between types of playoff teams.
So, are the 2018 Brewers a playoff team? Using Student’s T-Test to assess the first 81 games from sixty New Wild Card Era (2012-2017) teams and thirty-one midseason contenders that failed to reach the playoffs, I searched for teams with statistically significant differences in terms of average daily run differential win totals compared to the 2018 Brewers. Table Two demonstrates the results of my study. By isolating teams with statistically significant different average daily run differential win totals, I constructed a set of playoff teams and contenders that are reasonably similar to the 2018 Brewers; i.e., I constructed a set of playoff teams that demonstrate statistically insignificant differences in terms of midseason averages.
Below, Table Two includes midseason daily average run differential record, as well as the standard deviation of that average, plus the final actual W-L record and run differential record. Results are sorted by actual win total. Teams that failed to reach the playoffs are marked by an asterisk.
Table Two: New Wild Card Era Playoff Teams and Midseason Contenders that are Most Reasonably Similar to 2018 Brewers Midseason Daily Average Run Differential Record
These data include six of the sixty MLB playoff teams of the expanded Wild Card era, as well as four of the 31 midseason contenders I included in my original study of the era. Half of the teams ended up winning at least 90 games once the dust settled. Notably, the original study (see “Related Reading,” above) found that six playoff teams outplayed their expected run differential record by at least seven wins; four of those playoff teams appear in this survey.
This group features quite a range of ballclubs that are worth further exploration:
- Some clubs on this list are interesting because they appear to be at the beginning or end of “building” / “contending” windows. For example, the 2013 Cleveland, 2013 Pirates, and 2015 Cubs were clubs that were opening extended years of competitive play (the Pirates ended up being the least successful club in this group).
- By contrast, clubs like the 2015 Orioles, 2016 Rangers, and 2017 Rays were arguably clubs working within their last competitive window before some type of roster development strategy or correction was necessary.
- Additionally, what is worth noting is that some of these teams surged after posting mediocre midseason records. Here the 2013 Cleveland, 2013 Pirates, and 2015 Cubs are exemplary clubs once again.
- Of course, two of the clubs also had very strong midseason average run differential records (85 wins or better) without maintaining or improving that pace for the second half of the season.
- Finally, I feel compelled to speak to the exclusion of the 2012 Orioles and 2014 Royals from this survey, as both teams “feel” like the type of playoff club the 2018 Brewers could become. However, it is worth remembering that the 2012 Orioles had a very solid midseason average daily run differential record (86.9 wins) and actually declined (in terms of run differential) to close the season. By comparison, the 2014 Royals were an average 78.7 win team based on their midseason daily run differential, but they exhibited relatively low variance and therefore their T-test range did not capture the Brewers’ 2018 midseason average daily run differential record.
It is difficult to answer whether the Brewers will indeed reach the playoffs in 2018, but it is easier to understand the type of playoff profile they will have in recent history. With an elite bullpen, one indeed gets the sense that Milwaukee could easily out perform their run differential for the season and enter the playoffs without a phenomenal underlying performance in terms of RS / RA. The idea that this type of club exemplifies a team beginning a contending window also resonates with the sense that the Brewers are exiting a rebuilding phase and thus in a strange zone where they are not “truly” contending but no longer focusing solely on developing players at the MLB level also places them into a particular category. Finally, given the strong surges of the starting pitching staff, as well as some of the recent explosions of the bats exhibited over the last 33 games, one could also see the 2018 Brewers as a club that enters a Second Half tear and easily posts a win total in the mid-90s. All of this is suitable after an offseason that defined a very clear five-year window by acquiring Lorenzo Cain and Christian Yelich, boosting the sense that 2018 is the first “real” chance for this organization to reach the playoffs.
Photo Credit: David Kohl, USA Today Sports Images
Rowntree, Derek. (1981) 2004. Statistics Without Tears: A Primer for Non-Mathematicians. New York: Pearson.