The Milwaukee Brewers have been on quite a tear these last few weeks and it’s been hard not to get caught up in all the fun. They can hit, they can run, they like to flash the leather and they can pitch. For us Royals fans, this team looks oddly familiar.
Sure, there are the familiar faces littering the roster. It’s easy to get wrapped up in watching Lorenzo Cain, Mike Moustakas and even Erik Kratz (Erik Kratz!!) have postseason success. Throw in Joakim Soria, Jeremy Jeffress and even Manny Pina and at times it feels more like a Kansas City reunion than an October playoff run.
But maybe more than all of that is Milwaukee’s focus on their bullpen. The Brewers have had no qualms in October with pulling their starting pitching early and letting the pen take over the game. Milwaukee manager Craig Counsell has figured out how to utilize his relievers and configure them to help achieve the wins needed to parlay that into a trip to the World Series.
Hold on. That sounds really familiar. What other team rode one of the best bullpens in baseball all the way to the World Series? Yes, it would be the Royals. In fact, many within the game believe Kansas City’s use of high power arms in the back-end of the game was a precursor to about every single postseason team that has followed. The latest to steal the Royals formula are the Brewers and so far, so good.
But that begs an interesting question: If the Royals are the template, has Milwaukee improved on the original? Watching the Brewers roll out Josh Hader and Jeffress and Soria and Corey Knebel has really sparked a question of the two bullpens and just how comparable they really are. So lets figure out which is the better pen...
For this project I had to make a decision on which year would I go off of for the Kansas City. After some studying it appears we are going with the group from 2014, which was slightly better according to fWAR. This would also coincide with the Royals first appearance in the postseason this decade, as it is for Milwaukee.
Let’s start with some base numbers to start things off: Milwaukee relievers threw 614 innings this season, compiling an ERA of 3.47, an xFIP of 3.47 while striking out 10.38 batters per 9 innings. Meanwhile, the Royals pen only through 464 innings back in 2014, posting an ERA of 3.30, an xFIP of 3.54, while striking out 8.65 batters per 9. If we are talking WAR, the ‘Brew Crew’ had 7.1 while Kansas City only had 5.1 wins above replacement.
Going by the early numbers, it is already apparent the drastic shift in bullpen usage over the last couple of seasons. Milwaukee relievers threw 150 more innings this season than the Royals did in the 2014 campaign. Even going off of the 2015 Royals pen, the Brewers still tossed 75 more innings than the world championship squad. So in just four short years, there has been a noticeable difference in how pitchers are being used in the regular season, a change that is probably slightly attributed to how the Kansas City relievers were utilized in those two October’s.
With that said, the early numbers paint a picture of the Milwaukee pen being slightly better, as they had a slightly better xFIP, slightly higher K’s per 9 and a 2 win bump in WAR. But one can make the argument that the increase in WAR could be due to the massive difference in innings pitched, since WAR is an accumulative stat. The more innings you pitch, the more chances you have to increase your wins above replacement.
The strike outs are also interesting here, since most tend to go more off of K rate rather than per 9. The Brewers strike out rate this year was 27.6% (best in the National League), while the ‘14 Royals put up a 23% rate. Considering the increase in strike outs across the league over the last couple seasons and how more batters work on elevating the ball while hitting for more power, it shouldn’t be too surprising to see how these numbers panned out.
But how do the strike outs compare to the walks allowed? Going off of Walk %, the Brewers had a higher percentage, 9.5% compared to 8.8% by the Royals. When it comes to K-BB%, Milwaukee shines again as they posted a 18.1% while Kansas City had a 14.3%. Once again, part of this could be chalked up to the increase in strike outs. But it does appear on the surface that the Brewers are a pen built on more strike out relievers than the Royals.
That is backed up simply by looking at how many of the relievers on these two teams had a strike out rate over league average. League average in 2018 is 22.3% and Milwaukee had seven relievers with a rate higher than that. In 2014, the league average was 20.4%, and the Royals had only three relievers over that threshold. If we are talking the highest strike out rate, Josh Hader had 46.7% this year while Wade Davis had 39.1%. In fact, Hader and Corey Knebel both had a higher rate of punching out batters than Wade Davis did back in 2014.
So the numbers appear to skew a bit closer to Milwaukee’s side at this point, but we are not quite done breaking down the numbers. When it comes to WHIP (Walks plus Hits per Innings Pitched), the two teams are almost identical, as Milwaukee has a 1.25 and Kansas City pulled in a 1.24. This means the two teams were almost uniform in how many base runners they were allowing per innings pitched, which would essentially phase out the innings difference.
They were also similar when it came to Batting Average on Balls in Play, as the Royals posted a .293 batting average, while Milwaukee’s was .297. While a part of me wondered if the Brewers relievers were throwing slightly harder (based off the higher use of power arms in bullpens now compared to then and Milwaukee’s higher strike out rate), the truth is that the two teams had an almost identical average fastball velocity. Back in 2014, the Royals relievers averaged 93.5 mph while the Brewers this year averaged 93.9 mph.
In fact even if you tossed in fastball usage, the Royals relievers actually threw their fastball more on average than Milwaukee. The Royals relievers back in 2014 threw a fastball 63.2% of the time while the Brewers only threw it 61.8% this year.
I wondered if maybe Milwaukee was throwing more breaking balls than Kansas City did, but once again it was pretty close. The Royals used a slider 18.5% of the time and a curveball 7%. On the other side of the coin, Milwaukee used a slider 17.2% this year and a curve 10% of the time. While each team used a different breaking ball more often, the numbers are close enough to where they could probably meet in the middle.
If we really want to break things down, you start factoring win probability into the equation. In a very unsurprising development, these two teams were once again are ‘neck and neck’ in WPA; the Royals posted 8.09 win probability in ‘14 while the Brewers had 8.06. In a bit of a shock though, the two teams RE24 showed a big gap. Milwaukee posted an impressive 59.96 RE24 this year while the Royals had 31.10. Since run expectancy is another accumulative statistic, I do wonder here if the extra innings compiled by the Brewers relievers played a factor in the almost 29 point difference. If so, you wonder how closer the two teams would be if they had thrown the same number of innings.
There was one final factor I wanted to venture into and that was the defensive aspect of this conversation. It was very well-known that the 2014 Royals squad had a great defense and there was no way the pitching didn’t benefit from that defense. With that said, this Milwaukee team has also put up a solid defensive campaign, with Cain and Moustakas obviously being the two comparable links.
If we are going by defensive runs saved, it is no contest: the Brewers had 112 DRS while the Royals put up only 34. But there is also Defensive Runs Above Average (DEF), which measures a player’s defensive value relative to league average. If we are comparing each team’s DEF, the Royals win easily over Milwaukee, 65.5 compared to 29.9. I’m always a bit hesitant when using defensive metrics but the one thing you can take from these numbers is that both bullpens benefited from the glovework done out on the field while they were in the game.
So which pen is better? It appears to be a very close race and I almost feel skeptical in picking a winner. But if I absolutely had to, I would probably say Milwaukee’s is slightly better, with a few more weapons at their disposal. The one thing we can agree on is that we wouldn’t even be having this discussion if not for how Dayton Moore built his teams to weigh so heavily on the shoulders of the relievers. That template has become a staple all around baseball and not just by the Brewers.
It will also be curious to see where Milwaukee ends up. The Royals bullpen got them all the way to Game 7 of the World Series in 2014, and then a world championship the following year. Will the Brewers ride their pen to the World Series or will the high usage of their relievers be their downfall? It is a question we will know the answer to soon enough.