Bruin Sports Analytics
Are the Best MLB Teams Winning More Games?
By: Marcus Orwin
When the Los Angeles Dodgers fell just short of the San Francisco Giants in the 2021 MLB regular season, they made history -- no team had ever won 106 games and lost their division. This occurred at a time in which each MLB division contains just 5 teams in comparison to the 10 teams in each division from before 1969 and the up to 7 teams in each division from before 1995. In one sense, the Dodgers accomplished a truly rare feat -- only 6 teams have won 106 or more games in a single season since 2001. At the same time, what used to be considered historical is now approaching commonplace -- 5 of those 6 teams to win 106 or more games did so in the last 3 full seasons. This begs the question: Are high-win MLB teams becoming more common? If so, why, and is such a trend good or bad for the game?
Indeed, the threshold of 106 wins can be considered arbitrary. After all, the difference between 105 wins and 106 often boils down to one bad pitch or even bad luck. Instead, it might be useful to look at the standard deviation of win percentages by season -- this metric has no arbitrary cutoffs and is probably the most basic measure of record polarization.
There is a clear positive trend when looking at the standard deviation of team records by win percentage. However, there are still some issues with this metric -- namely, it doesn’t necessarily tell us what we want to analyze. 2013 is a great example of this flaw, as prior to 2018 it was the highest measure of deviation even though no team accumulated more than 97 wins. Rather, the high deviation has more to do with the Astros “tanking”, or losing with the purpose of obtaining higher draft picks. This also explains why 2018 and 2019 have a higher deviation than 2021, as the Orioles were worse in the former two seasons than almost any team in Major League history. Thus, standard deviation is far from perfect when analyzing the prevalence of high-win teams, but the positive trend is still quite revealing.
We can also study these trends by changing the win threshold from 106. Perhaps the most important win total in this case is a 100 win season -- though this threshold is also arbitrary, reaching 100 wins has always been recognized as a landmark achievement by fans and owners alike.
The first graph displays the frequency of MLB teams with 100 or more wins by decade, starting in 1961 (the year in which MLB's schedule expanded to where it is today) and excluding 2020's shortened season. Obviously, there are some caveats -- for one, there are more teams today than there were in decades past. Still, this graph shows the prevalence of 100+ win teams today, albeit not a shocking or entirely unprecedented prevalence. However, as is clear in the standard deviation graph, there has been a clear uptick in polarization in just the last few years, so grouping the 2010s as a whole is a little misleading.
This is where the second graph is useful -- it zooms in and breaks down the past 20 full MLB seasons (again, excluding 2020) into 5 groups. This shows a much stronger trend, with there being 13 such teams over the past 4 seasons compared to 2 in each of the 3 intervals before 2017. While the first interval is somewhat similar to the most recent interval, the era it encompasses (2001-2004) was also characterized by highly polarized records.
Whether looking simply at win percentage or certain thresholds of wins, it’s clear that there are more high-win MLB teams now than ever before. However, the cause for such an uptick in 100+ win teams is less clear. The most common theory is that teams have begun to “tank”, such as the aforementioned Astros in the early 2010s. However, the tanking strategy was fairly popular in the early and mid 2010s -- a period of relatively few high-win teams. There is no reason that tanking would cause 3+ teams to win 100 games each year when there are arguably fewer teams purposefully losing now than there were a few years ago. Instead, it’s possible that this era of baseball is one in which new resources are being discovered -- ones which only certain teams are taking advantage of. This would certainly explain the Giants and Rays, for example, as those two teams both reached 100 wins this year by hiring an unprecedented number of coaches and statisticians, respectively.
When looking at the cause for a rise in such strong teams, the question of spending is also paramount. In 2019, 100 win teams spent approximately 31% more than the average team, and in 2021 that number slightly increased to 34%. It’s interesting to compare these numbers to a previous era -- in 2002, 100 win teams spent ~28% more than the league average, but that number jumped to over 60% higher than average in 2003. The upshot of these trends is that baseball can be unpredictable. In general, the best teams spend more money than most others, but the 2019-2021 Rays and 2002 Athletics are both notable exceptions that wildly change those numbers. While 100 win teams are expected to spend the most money, this is often not the case, undermining the idea that money is the most important factor in a team’s success.
As much as MLB fans love watching their favorite team compile tons of wins, concerns have rightfully been raised as to whether or not the prevalence of multiple 100+ win teams necessarily means the existence of teams with 100 or more losses. The idea that such record polarization harms viewership overall is fairly intuitive -- fans of poor teams have little to root for, and even great teams often run away with their division so early that their games tend to be low stakes towards the end of the season. Fortunately, a team reaching 100 wins does not necessarily imply an equally poor team. Take the 2017 MLB season, for example. Three teams reached 100 wins, but not a single team lost 100 games.
Overall though, it’s unclear whether or not record polarization is a negative influence on viewership. It’s no secret that there has been a decline in Major League Baseball’s popularity -- World Series viewership numbers, for example, ticked up in 2021 but were previously in a decline that lasted years. However, this correlation may be a mere coincidence, as the early 2000s are a clear counterexample. As can be seen in a graph above, from 2001-2004, 10 MLB teams achieved 100 win seasons -- in fact, this era is the only one comparable to the current era in that respect. Interestingly, baseball was incredibly popular at that time for a number of reasons, but the prevalence of great teams certainly did not hinder viewership.
At the end of the day, most trends in professional sports (and Major League Baseball) are cyclical. While this era of increasingly polarized team records is somewhat unprecedented, it’s likely that another shift will occur in the next few years. Still, it’s certainly interesting to witness an era in which there are a multitude of incredible teams each year.