The Fantasy Architect: How to Reduce Playoff Randomness in Your League

No two fantasy leagues are the same. There are lots of variables, each with many different options, that can be tweaked to create a unique experience. Your old home league settings probably look a lot different than a highly competitive league that you started recently.

In this offseason series, we’ll take a look at various designs for your league, and how those designs affect the fantasy manager experience. Of course, there is no ‘one answer’: every fantasy manager wants something different. This series is intended, in part, to help you explore what’s out there.

All data, unless otherwise specified, is from nflfastR.

Playoff Luck

In the first entry of this series, I discussed paths to randomness reduction over the regular season. Our main variable of interest was the probability that a ‘skilled’ team makes the playoffs in their league. However, there is another, a perhaps more important side of the ‘luck’ coin: once you are in the playoffs, who actually wins the championship?

We all have stories of unlikely postseason runs, which were either legendary or actually upsetting (depending on which side you were on). Everyone is familiar with the arc of the #1 overall seed who storms into the playoffs on a 10-game win streak, only to fall at the hands of a team that snuck in and happened to make some adroit late-season waiver pickups (a la Rashaad Penny and Jaret Patterson in 2021).

We’ll be using a standard paradigm as a launching point: a 12-team league where the top 4 teams make the playoffs and each round is one week long. In the first entry of this series, we defined a ‘reasonably skilled’ team as one that has a 53% win probability in a single matchup (an ‘average’ team has a 50% win probability). You might define a ‘skilled’ team as having a better (or worse) chance of winning each game, but we’ll be focusing on the relative changes in this probability.

Our variable of importance will be this skilled team’s championship probability given that they are in the playoffs. In the base case, this is 28%, or the probability of winning two games in a row (53% squared). This 28% mark is higher than pure randomness (25%, or one of the four teams), but not that much higher. Let’s see how different policies affect this number.

Getty Images / Tim Warner

Two-Week Rounds

One of the most common adjustments is to make each playoff round two weeks long. The team that scores the most aggregate points across the two weeks wins the round. For example, the championship takes place over Weeks 16 and 17, and the team that scores the most total points in these two weeks wins (even if they scored less in one of the weeks by itself).

This intuitively reduces randomness, similar to how the NBA playoffs, which feature 7-game series, are less random than the NFL playoffs (win or go home). An underdog might get lucky and win a single game; it’s harder to get lucky twice. The same concept applies with fantasy.

We can measure the impact of a two-week round with a simulation that I outlined in the first entry, where the ‘skilled’ team has about a 3.3% advantage at each position. Surprisingly, when the skilled team has a 53% win probability in a single week, their win probability over two weeks only jumps to 54.3%, which means their championship probability only jumps to 29.5% (54.3% squared), or a 1.5% increase from the base rate.

This is a much lower increase than I expected, which is unfortunate because this policy comes with a huge cost. The 8 managers who don’t make the playoffs now have two less meaningful weeks of fantasy football, because the playoffs stretch out that much longer!

Double Elimination

This popular tournament format is similar to two-week rounds in the sense that you have to lose twice to be eliminated. Basically, if you lose a game, you get sent to the ‘losers bracket’, where you have a chance to keep winning and make it into the championship (where you have to win twice). If you lose in the losers bracket, your season is over.

I ran a simulation, and a skilled team with a 53% chance of winning each game has a 32.2% chance of walking away with the trophy. This is a larger mark than the 29.5% championship probability from a two-week round, which is enticing when reducing randomness. However, the downside is even worse: a four-team double-elimination bracket can take up to 5 weeks to conclude, which means you must allocate five weeks into the fantasy season schedule. That’s one less week of fantasy football for the 8 teams that don’t make the playoffs (compared to the two-week rounds).

Bye Weeks

Another approach, which matches the actual NFL system, is to give the top seeds a bye week in the first round of the playoffs. In this setup, the top 6 teams would make the playoffs, and the top 2 seeds would automatically get a semi-finals berth.

The championship probability calculation is actually the same here as the default setting. The ‘skilled’ team has to win two games to win a championship which, at a 53% win probability for each game, yields a 28% chance. Although the level is the same, the relative advantage has changed: an average team who didn’t get a bye week has a 12.5% chance of winning a championship (50% each week for three weeks). Therefore, a skilled team has more than double the chance of an average team in the playoffs of winning a trophy, compared to in the default, four-team playoff where an average team has a similar chance (25%).

The advantage to this approach, then, is allowing for more teams to make the postseason (and play more fantasy football) while creating a much higher relative advantage for top teams. One potential downside is that bye weeks can be boring, and even frustrating if your team performs really well on their week off. Still, most managers will be happy enough to have secured a bye to not actually mind!

Home Field Advantage

I mentioned in my last article that my home league has a +7 point home-field advantage in the playoffs for the higher seed. The reason is simple: to reward the teams that performed well in the regular season by reducing their exposure to bad luck. We’ve liked this policy, especially because it reflects the real NFL, where higher seeds maintain home-field advantage in the playoffs.

By adjusting our simulation, we find that each additional point increases the championship probability of the ‘skilled’ team by 0.7% (this is for teams that score about 100 points on average, so it might be different for your league). This is actually a large number since the implication is that just a +2 home-field advantage has about the same effect as a two-week playoff round (1.5% championship probability increase). A full +7 point advantage would add 5% to the championship probability.

Conclusion

We’ve seen methods throughout this article that reduce the randomness in a fantasy postseason. Often the tradeoff, though, is reducing the length of the regular season, which affects the managers who don’t make the playoffs. Bye weeks are an option that increase the relative likelihood of a championship for a skilled team while keeping more teams in the mix; even simpler is a home-field advantage, which is a direct way of increasing a team’s win probability. Hopefully, you’ve seen something that fits your fancy for the upcoming postseason!

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