The 2021 MLB postseason is less than a month away and teams are still fighting to win their division or grab one of the two wildcard spots in their conference. In case you don't know the system for the MLB postseason, the postseason consists of 5 teams from each conference, the 3 division winners and 2 wildcard spots. The wildcard spots are held by the top 2 team records in the entire conference that were not division winners. For example, if the Red Sox did not win their division then their team record would be compared to every other non-division winner and if their record was the best or second best among those teams then they would get a wildcard spot.
In the American League, the Astros, White Sox, and Rays are leading their respective divisions and are in good position to keep hold of that lead spot. Therefore, when looking at the wildcard race in the American League we will only look at the Yankees, Red Sox, Blue Jays, A's, and Mariners. In the National League, only the Brewers have a strong hold over their division leading spot, but the Braves and Giants are currently leading their respective divisions and therefore won't be considered part of the wildcard race in the National League. Lastly, the Dodgers have secured one of the wildcard spots in the National League since they are almost 20 games ahead of all teams that are not division leaders.
Chart 1 below shows the four wildcard teams over the last 5 years along with some of their hitting and pitching statistics taken from MLB.com. This does not include the 2020 season since the season was shortened to just 60 games instead of the usual 162 game schedule, and the playoff format was expanded so that the top 2 teams in each division along with 2 wildcard teams made the playoffs.
Chart 1
We can see the statistics from MLB.com of the 5 wildcard contenders in each conference for the 2021 season below in Chart 2. The statistics are taken before the games on September 14th have been played.
Chart 2
Batting Average (Avg)
We see from Chart 1 that wildcard teams have a team batting average of 0.244 or higher, but on average wildcard teams have a 0.251 batting average or higher. Based on this we see in Chart 2 that only the Red Sox and Blue Jays have a batting average higher than the average, but the Reds do reach the 0.244 batting average expectation. Teams close to this expectation include the Cardinals, Phillies, Mets, and Padres.
On Base Percentage (OBP)
OBP has never been lower than 0.315 among wildcard teams over the last 5 years, but average between 0.32 and 0.33. Teams that satisfy the average are the Red Sox, Blue Jays, Yankees, Reds, and Padres. The Athletics, Phillies, and Mets are all greater than or equal to the 0.315 minimum OBP, and the Cardinals are close to the minimum.
Slugging Percentage (SLG)
Wildcard teams have never had a SLG lower than 0.396 and average around 0.43 over the last 5 years. Only the Red Sox and Blue Jays meet and exceed the average, with the Reds being very close and could very well reach the average of 0.43 by the end of the season. Every other team except for the Mariners are above the minimum but below the average.
Win Percentage (Win%)
Win percentage, in terms of capturing a wildcard spot, depends on the strength of the conference. For example, this year the Athletics have the worst win percentage of the 5 AL wildcard contenders, but that same percentage would be the best among the 5 NL wildcard contenders. That said, teams tend to have a win percentage between 55% and 60% with the lowest being 52.5% in 2017. Only the Red Sox, Blue Jays, and Yankees have win percentages between 55% and 60%. Every NL wildcard contender has a win percentage less then 52.5% with the Reds being the closest at 52.1%.
Earned Run Average (ERA)
Now we look at pitching statistics starting with the teams' ERA. Wildcard teams have a 3.88 ERA on average with 3.21 being the best and 4.59 being the worst over the last 5 years. Only the Mets, Padres, Yankees, and Blue Jays have a better ERA than the 3.88 average.
Walks and Hits Per Inning Pitched (WHIP)
Wildcard Teams have had an average WHIP between 1.25 and 1.3. The best WHIP was 1.15 in 2015 by the Cubs, and the worst WHIP was 1.38 in 2017 by the Rockies. Teams that have a WHIP at or better than the average include every wildcard contender except the Red Sox, Reds, and Cardinals. The Yankees have the best WHIP among the wildcard contenders at 1.2.
Opponent Batting Average (Opp Avg)
Keeping an opponent from getting base hits against you is very important in making a push for a playoff spot. Over the last 5 years the average Opp Avg is 0.245 with the lowest Opp Avg being 0.228 in 2017 by the Yankees and the highest Opp Avg being 0.266 in 2017 by the Twins. The Blue Jays, Yankees, Athletics, Reds, Cardinals, Mets, and Padres all have Opp Avg lower than the 5 year average with the Cardinals having the best at a 0.233.
Looking at all of this, the Blue Jays were the only team to meet each statistic's threshold. The Yankees met each pitching threshold but came up short in two of the hitting statistic thresholds. Whereas the Red Sox were the opposite and missed all of the pitching statistic benchmark, but did meet all the hitting statistic benchmarks. The National League teams struggled to reach these statistical benchmarks except for the Padres who met four of the seven statistic thresholds.
Based off these numbers and what past statistics wildcard teams had to set to earn a spot, the Blue Jays and Yankees are the two teams that will occupy the AL wildcard spots, and the Padres will take the last wildcard spot in the NL that isn't being held by the Dodgers. There is still plenty of baseball to be played and these numbers will likely look much different by the end of the season. Teams can go on a hot streak or cold streak at any moment. Enjoy these last few weeks of regular season baseball as teams fight for a chance to compete for a World Series title, and get ready for playoff baseball to start soon.