What the Numbers Tell Us about the Brewers Luck

Even with all the resources we have available now, the concept of luck in baseball might be impossible to determine.  A lot of the formulas, numbers, and statistics that are floating around are only what you make out of them. The concepts and the ideas of the graphs and numbers looked at here are used interpret different things, but when combined they may help come to one singular conclusion. Have the Milwaukee Brewers been lucky? Or unlucky?

Firstly, it’s important to determine what luck in baseball is. “Luck” can then be applied to actions or events where the end result wasn’t affected by the skills of the players. More importantly, it can apply to an outcome where the skill of the event or action doesn’t equate equally to the end result. Examples of this can include hard hit balls that turn into outs, or poorly hit balls that end up being hits. Luck can have to with whom the ball is hit to, when, and where the ball is hit. Sometimes batters can only hit the ball and hope. 

Let's start with the Brewers bread and butter, pitching. For their pitching, I’ll be using Fangraphs percentages (shown below) to help make inferences about Brewers pitching. The Brewers pitching staff has the highest Soft% (Soft Contact Percentage) in the league, which is a positive thing, because any ball batted ball that registers under Soft% is interpreted to generate the least amount of bases per plate appearance when naturally compared to Hard% and Med%. If batted ball events labeled as Soft% are more likely to be outs, you’d figure the Brewers staff would generate more outs, and therefore give up less runs when compared to the rest of the league.

The Brewers also lead the league in K/9, eliminating the possibility that the Brewers are giving up too much contact to expect to be successful in the pitching department. The Brewers pitching staff also ranks bottom five in difference of staff slugging percentage and expected slugging percentage, meaning that the Brewers staff could be giving more extra bases than they actually should be too. Because the Brewers strike out the most hitters, and when those hitters make contact, it has the highest chance of being weak, you’d could reasonably assume the Brewers pitching staff has given up the least (or near the least) amount of runs.

In actuality, the Brewers rank 9th in league wide ERA. If you extrapolate from all of this data, you could come to the conclusion the Brewers have been hampered by a bit of bad luck when they toe the slab.

Numbers via Fangraphs, accessed 6/17/2022

Another way to extrapolate luck on the pitching side is homerun to flyball rate (HR/FB). This takes into account that sometimes pitchers can't control whether a well-struck flyball ends up on the warning track, or if it ends up in the outfield seats. The league average for HR/FB is 13.6% in 2022, and the Brewers sit at 13.3 percent, meaning Milwaukee's pitchers haven't been hampered by bad homerun luck so far.

Furthermore, If your goal is to prove the Brewers have in fact been lucky, you could mention the fact the Brewers pitchers have the 8th smallest difference in XwOBA and wOBA, and both their Hard% and Med% are league average. This certainly doesn't prove they've been lucky, but you could argue they haven't been unlucky either.

All of that can be a lot to take in, but the conclusion from this section is simple. If you want to conclude the Brewers pitchers have been the recipients of bad luck, you should probably point to the injuries that have plagued the Brewers over the past month. Oppositely, you could argue the Brewers staff has been benefactors of some luck, but it's a better conclusion to point to how elite some of the players who make up that staff instead.

What about the Hitters? First, we can use Baseball Savant to compare the differences of the expected metrics and the traditional statistics. The Brewers have been quite literally average, ranking at either 15th or 16th in the league in batting average, slugging percentage and Quality of Contact. Not to mention, If you compare the Brewers to the MLB average in the expected hitting metrics (xBA, xSLG, and xwOBA) you'd see the Brewers have been nothing extraordinary, just average. Using these 3 differences, you could conclude the Brewers offense has been neither lucky or unlucky.

Graph via Baseball Savant, accessed 6/17/2022

Then there's BABIP. Over the past couple years BABIP has been the poster child of bad batted ball luck. If you're unfamiliar, BABIP stands for batting average on balls in play. Much like FIP for pitchers, BABIP eliminates the plate appearances that don't result in a ball being put in the field on play, giving you a batting average for batted ball events only fielders can affect. Batters with high BABIP are often assumed to be lucky hitters who are having more hits fall their way, while players with low BABIP are often assumed to getting hits taken away from them at a higher rate than normal.

The problem with BABIP is it doesn't account for how well the ball is struck, or where it is hit. BABIP isn't completely skill dependent as well, as good players often have high BABIP, and good pitchers often have low BABIP against. If you're a believer in BABIP, the Brewers team BABIP is .283, good for 25th best in the league. By those standards alone, the Brewers offense has been pretty unlucky.

If you want to conclude anything based on luck about the Brewers offense, I'd refrain from making conclusions about the group as a whole, and implore you to take deeper looks into individual players. Players like Christian Yelich, Rowdy Tellez, and Omar Narváez have larger discrepancies in their metrics than any team ever will. 

Lastly, I'd be hard pressed not to mention some of the formulas that have been developed that try to quantify luck in baseball. One of the more well-known is the Pythagorean expectation (See below) developed by Bill James, whose name is tied to the early use of Sabermetrics. The theorem has been well refined, as often teams only vary from their expected win totals by a few games by season end. Using the Pythagorean expectation to measure luck isn't really its whole purpose, so drawing conclusions about luck won't be featured here.

Another formula created to measure luck is cluster luck. This is the concept that teams have little control over how their hits are clustered together. If you're not one to believe in timely hitting, then the Brewers cluster luck statistics rank them 7th in the league, meaning they've been quite lucky in that department. However, it is worth mentioning that 2 teams in the NL Central, both the Cubs and Cardinals are ranked higher than the Brewers at the moment. 

To some, maybe this conclusion is anticlimactic. There was no firm statement on what to make of the Brewers luck. Truthfully, baseball is too far into season for any of these metrics and numbers to have small enough sample sizes to the point of making any logical conclusion about luck. It doesn't mean these numbers are unimportant or meaningless however. Luck will even out over the course of a season, but on a game-to-game basis, you can really see some of these obscure numbers take effect.