Across the internet parts of baseball fandom, there has been an almost universal dislike for the expansion of the playoffs to 16 teams to continue beyond the 2020 season. I have seen no-one actively liking the idea and just a few being neutral until there were more confirmed plans.
With the main concerns being the rewarding of mediocrity that could drive down spending by teams, and devaluing the worth of the regular season.
There are various reasons why this could come about so, let us review the 2020 playoff system and the previous system, to show the difference in winning odds for each round and the overall World Series winning odds. Then I’ll make some suggestions for expanded playoffs which should mitigate or remove these issues.
There are going to be some estimated probabilities for here on; these have been calculated using the average win totals since the expansion to 30 teams, and by looking at FanGraphs’ odds for head-to-head games for these win totals. This does not account for the fact that the playoff schedule is different from the regular season (needing less than five starters) and some teams transfer to this better than others.

Making the playoffs

Historically, to guarantee that you would make the playoffs in the 10-team format, you had to get 94 wins. 90 wins would have gotten you there nine times out of 10, and 87 wins is the more-likely-than-not point. For 16-teams those values change to 86, 85 and 81 wins, respectively.
Right off the bat, here is what concerns most people, a reduction in the win total required to make the postseason. But this eight to six-win decrease in itself isn’t too much of an issue, especially if there is still an incentive for the top teams to push for 100+ wins. There isn’t, but we’ll get to that.
Also, you can see here that several teams, 31 teams over 22 seasons, would had made the 16-team playoffs with a losing record. Including the 1999 Chicago White Sox whose 75-86 record would have been good enough to finish 2nd in the AL Central. Whereas no team, with a losing record, would have made the 10-team playoffs, if it had been used all these years.
The Wild Card Round

It is kind of obvious to say but the division winners lose quite a significant chance of making the divisional series, but the amount might shock you. MLB is not like the NBA, the difference between the first and eighth seeds is much smaller. Even with the first seed at home, they have roughly a 70% chance of winning each game, which translates to 79% over the series.
The 16-team playoff system decreases the bonus of winning your division compared to being runner up. Before you had the bye, and now the best your odds could be are 79%. And while there is some incentive to be seeded first, the gain in odds you have over the third seed is less than the odds you lost from losing that bye.
And with these odds across both leagues, we would expect on average two or three of the higher seeds to lose in the wild card round.
The Divisional Series

There is little impact (<1%) to the first seed team here, as they are still playing the winner of the 4v5 game; it’s just the fourth-seeded team is slightly more likely to be the opponent. But for seeds two to five, their odds improve as there is now a chance that they might not be facing a higher-ranked side in the divisional series. Therefore, once again you are decreasing the worth of performing best in the regular season.
The eagle-eyed of you may have spotted a peculiarity in that table – the odds of the seventh seed winning are better than the fourth, fifth and sixth seeds. That is because if the seventh seed managed to upset the second seed, they would face the winner of 3v6, and historically the seventh seed has a better record than the sixth seed, so would be favourite in that game. Also, even if they did have to face the third seed, that was an easier task than facing the first seed (like the fourth and fifth seed would).
The Championship Series

Here is the first part where all of the seeds in the 10-team system have improved odds at getting through a round in the 16-team system. The increase ranges from 3-5%, but once again, due to the fact they might be facing lower-seeded teams, the top teams are slightly more likely to perform better.
But this small uptick in the CS win-percentage does not counter the decreased likelihood teams had of making it to the CS, and all division winners have lower odds of making the World Series. One thing we do see though is that the odds for making the World Series lines up with teams-wins, and not their seeding.
The World Series

There you have it. If we had the average teams from the last 30 years, the odds of the team with the best record winning the World Series decreases by 2.9%. Even though it is a 12% reduction in that team’s chances, to be perfectly honest, it is lower than I thought it would be.
The likelihood of winning the World Series if a team makes it there improves for all teams because there is a chance that you would be facing a lower seed than was possible in the 10-team format.
The top three team’s lose out but the fourth and fifth seeds make gains with the fourth team increasing their odds by 50%. The six (three AL & three NL) teams that would not make the postseason in the historical system combine for World Series-winning odds of 5.6%. So, we should roughly expect that once every 20 years.
And once again we see the odds for winning the World Series lines up with teams wins and not their seeding. Which suggests that seeding them in this method does not give any benefit over how well they have performed in season.
Summary
As I said above, the change to 16-team format does not actually reduce the odds of a top team winning the World Series as significantly as I thought it would, but there is still a reduction. Combining that with the thought that you can now make the postseason with eight fewer wins, the risk/reward for teams to spend money on players changes for the worse.
These are the eight wins that teams have had to spend the most to get; these are not coming from having a few extra Quad-A players in the 40-man. These are coming from signing big free agents or locking down internal talent beyond arbitration. Not spending this money and still having a chance of making the playoffs will make the owners incredibly happy – they can say they made the playoffs to the fans.
This may disincentivise teams tanking, as they should all be able to assemble a .500 team without too much investment. This will not come from adding high quality players to their squad; this will more than likely come from teams plumbing the depths of the minor league free agents and their farm system in hopes of discovering 2-WAR players.
Other Effects
Are there other reasons for wanting to have the expanded playoffs beyond the owners potentially spending less? The simplest one is once again money. More playoff games means more nationally televised games which means more to the owners, and in this case, the players as well.
Also, more eyes on the game. I didn’t grow up watching baseball so this may be more conjecture than fact, but for me as a kid, if a local sports team was doing well in the league or a cup, it would draw my attention to that team. I am talking younger kids here probably even preteens. Having more teams have games which are genuinely important could have a positive impact on their view of baseball. Yes, there is a counter argument that it makes regular season games less important, but that is only true if the expansion is not done correctly.
Suggested improvements
For an expanded playoff system to work for me, there must be two major differences from the one we have for 2020. Firstly, there needs to be a smaller chance of teams with a losing record making the postseason. Secondly, there needs to be greater benefit for teams having better win-loss records, so that there is something for teams to aim for beyond just making the playoffs.
If the playoffs were expanded to 12 teams, there would have been just one team with a losing record that would have made it. And for a 14-team format, there would have a further seven teams with losing records. While we still have 30 teams in MLB, I do not think having a 16-teams format is the number to go to. An expansion to 12 or 14 teams is reasonable without giving opportunities to many below-average teams.
Now for the part which you could make difficult/convoluted if you wanted – devising a 12 or 14 team playoff system that incentivises teams winning the most games. There are tonnes of methods one could incorporate here, but you cannot go too far from the status quo otherwise it will not be accepted.
And truth be told, you don’t have to go too far to find, in my book, a better system. If you choose the 16-team seeding and format, but give byes in the WCS for when you have fewer teams, the odds would look like this.

Personally, I like the odds from a 14-team tournament where the team with the best record gets a bye through the Wild Card Series. That stark difference between the first seed and the second seed should really push teams to continue to try and get every win at the end of a season.
I like the playoffs to still have some randomness to it, but I still want the best teams to make it to the World Series, and this 14-team format does that for me.
Frankly, the expansion to 12-teams with the three-game Wild Card Series, does not impact the overall odds that much. So, this could be the happy medium that most people should be okay with.
You can spice things up to have the teams choosing who they want to play in the Wild Card Series. Although this could be described as gimmicky, I like this as it brings the final few games of the season into more scrutiny, and will give fans further things to discuss and analyse.
Finally, if the purpose of expanding the playoffs is to get more eyes on the sport at the crucial moments, then expanding to 12 or 14 teams is a reasonable suggestion. The only reason to go to 16 teams in my book, is if it is a pure money-grabbing and move-saving exercise from the owners.

Russell is Bat Flips and Nerds’ resident analytical genius, and arguably Europe’s finest sabermetrician. If you’re not following Russell on Twitter @REassom then you’re doing baseball wrong.
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