Keys to Playoff Fantasy Success - Using Math to Win Your Playoff Fantasy Football League

Jordan Reed has emerged as a top-flight fantasy option

If you are anything like me, you're probably looking to the NFL playoffs as a chance for some fantasy football redemption. That's not to say I did poorly. In fact, I finished just above middle of the pack in all my leagues, even sliding into the final playoff spot in one (call it a product of drafting Jeremy Hill and Jimmy Graham in all leagues). Yet, the NFL playoffs offer a different approach to fantasy that can knock some less experienced players off course. Unlike the regular season, the number of games each player will play is not the same (excluding injuries of course). For this reason, a players individual skill is not the sole determinant in their value. Take someone like Jordan Reed, tight end for the Washington Redskins. He's been the second best scoring tight end in fantasy this season. However, there is a high likelihood (call Washington's first round game with the Packers a pick-em) he only gets one game of production in the playoffs. Compared with someone like Travis Kelce (the fifth best TE option this year) who plays on a team with potential for a deep playoff run, Reed may not be the better option. Easy enough to understand intuitively, but how can we break this down mathematically to give us the best shot of winning, or at least drafting well? I'll show you.

The key to this computation is a calculation of expected games played. It doesn't matter how many games a team wins in our case, only how many games our players have the chance for production. The most basic way to calculate this is with expected value. It should be noted that expected value gives us only a marginally accurate probability (and technically shouldn't be used in the case of dependent events), as the number of games we expect a team to play are not entirely independent of one another. The higher the probability a team has to make it to the divisional round inherently drags up the probability they will make it to the Conference Championship. Still, expected value will give us a working assessment of the probable value each team holds in terms of number of games played. For this calculation we'll use numbers from the guys over at FiveThirtyEight, predicting the playoffs based off of each team's ELO rating.

FiveThirtyEight provides some great mathematical and statistical analysis, including these playoff odds for each team

Expected Games Played for each
Team in NFL Playoffs

In order to calculate the expected games played, one needs to multiply the percent chance a team makes a given round by the additional one game that round would represent. For instance, Carolina has an 100% chance of making the divisional round (they have a bye, will automatically play in that round), a 61% chance of making the Conference Championship, and a 38% chance of making the Super Bowl. When multiplying these values by one game a piece, we are left with 1 game + .61 games + .38 games with a total expected games played of 1.98 games. Carrying out the process for all teams gives us the following expectation.

Taking this data gives us a good approximation for each players projected points. It should be noted, that this gives us an expected value, one that would be based off of the aggregate result of multiple playoffs of the same construction. Thus, the variance in the data will be somewhat large. We can weigh this variance in our favor by picking players from teams with a high expected number of games, but also a high potential to exceed their potential games. This essentially refers to picking players on the best teams playing in the Wild Card round of the playoffs. Taking a side by side look at Seattle and Carolina we see that both teams have a similar expected number of games. However, Seattle has the opportunity to play, at most, four games, while Carolina can only play a maximum of three. 

Taking the expected number of games played for each team, and multiplying by the average fantasy points per game of each player will give us a good prediction of each player's expected production in the NFL playoffs. Of course, this data only gives us a clue of relative value for each player. If you were to have picked Kurt Warner and Larry Fitzgerald of the 2008 Arizona Cardinals in playoff fantasy football, you most certainly would have won, as they went all the way to the Super Bowl as a six seed. Additionally, it should be noted that using average fantasy production does not account for players on hot streaks (Kirk Cousins and Jordan Reed) or coming off of injuries (Marshawn Lynch). For evaluating those cases, you'll just have to use your gut. (Below are the computations for your benefit)

An Interesting Case
In my playoff league, we are using a multiplier to compensate for draft position. Thus, the X-1 player taken at each position will get a multiplier of between .05 and .15, depending on position, added to their score. For instance, the third Quarterback taken will get an additional .3 (.15 times 2) added to their score, meaning their value is 1.3 times their original value. The key is to draft high at premium positions (steep fall off in points such as Running Back and Tight End) and draft late for positions with great depth (Kicker and Wide Receiver). In this regard, the expected value calculation is invaluable in determining when to draft a position as depth or lack there of is only exacerbated.