Never Start the Wrong Guy Again

Fantasy Math simulates your matchup thousands of times, taking into account factors regular ratings can't:

  • whether anyone you're considering is correlated (playing in the same NFL game) as anyone else in your matchup
  • each players variance (boom or bust-ness)
  • whether you're favored and by how much — interacts with the above

Fantasy Math takes it all into account

Here's how it works

1. Enter your matchup

Including scoring systems, any midweek points (so you can run it after the Thursday night games, etc).

Once you enter your team, FM will remember them so it's easy to enter them again.


2. Behind the scenes, Fantasy Math models the distribution of each player's outcome

The computer simulates your matchup thousands of times, sampling from each player's probability distribution.

These distributions are fit using the expert fantasy consensus.

The more the industry disagrees about a player, the wider his range of possible outcomes.


3. Fantasy Math samples these distributions to simulate YOUR matchup

The computer simulates your matchup thousands of times, sampling from each player's probability distribution.

Right: 15 random sims from a few of these players (in reality the model does 1-10k samples for each player on both teams, as well as all the guys you're contemplating starting).


4. These samples are correlated

These simulations not only fit well (gray lines above), they're also correlated . For example, our opponent here had Watson + David Johnson, who were playing the Ravens and Mark Andrews. Here's the correlation matrix of these simulations:


You can see Watson and DJ's simulations are positively correlated at 0.13 (historically the correlation for pts between a starting QB and RB). Watson is also positively correlated with Andrews and Lamar Jackson, and (strongly) negatively correlated with the BAL defense.

These are just a few players. The Fantasy Math Model factors in ALL of the following correlations:


5. You get back who to start to maximize your chances

Once you click submit, and FM has simulated every scenerio (only takes a few seconds), you get back who you should start.

Along with your probability of winning with each player, FM also returns how often you can expect the advice to be WRONG (a backup outscores the reccommended starter)

It also tells you how often this decision will cost you your matchup (LOSE).


Finally, you also get a closer look at each individual player, as well as a look at your team (with the recommended starter) vs your opponent.


6. Also get in depth looks at the players on your team.

Toggle individual players distributions by position to see where you stack up vs your opponent and where you might improve.

It's also useful for sending people trade offers, showing them how a proposed trade helps their win probability this week.

Sound good?


“ outstanding way to visualize the choices we make every week and why there are not necessarily one size fits all right answers, different curves make more sense for different lineups/matchups.”

Sigmund Bloom

What People Are Saying

"I freaking love this. It's a beautiful idea and so far looks like a great execution of it."

— Dylan Lerch, aka u/quickonthedrawl

"No other tool I've ever come across has done this... I've considered [incorporating correlations] as a competitive advantage of mine for a number of years, but wasn't able to properly and consistently quantify those values in a truly objective measure..."

— Adam Harstad

"I think @nathanbraun is one of the sharpest dudes around."

— Adam Harstad

"It’s an incredible site . I have no idea how you worked the math into this."

— Ben R

"..helped me to two championships last season!"

— John M

"...this is the first site I have seen that looks like it might match the standards I'd have for a subscription service."

— David S

Rebuilt Models

Fantasy Math has always projected performance as distributions, but up until this year it was a single, closed form distribution.

In the two pictures below — note: read this if you aren't sure how to interpret these — the blue line is how the top 5 ranked RBs performed from 2017-2019, standard scoring.

The old model is the single gray curve on the left. It fits performance pretty well, but there's only so much you can do when you're working with a single curve.


OLD Model


NEW Model

The NEW model uses probabilistic, Bayesian and MCMC sampling methods to fit fit thousands of distributions and better represent the curve. You can see how the model (all the gray curves) captures actual performance (blue) a lot better.

The FM model calculates thousands of these distributions for each player, every week.


Above, how the model does on QBs. Sorry the blue line is kind of hard to see... since it's right in the middle of the model!!!

Get Fantasy Math for 2022

Purchases handled securely via Stripe and SendOwl.

Buying will give you a license key that you can use to access the app.



Includes access to correlated simulations to get advice specific to YOUR matchup.

  • Run the model with 1,000 simulations

  • Will get you 95%+ of the way there and put you ahead of your leaguemates for sure.

Buy Now

30 day money back guarantee!



Includes access to correlated simulations to get advice specific to YOUR matchup.

  • Run the model with 5,000 simulations

  • That's 5x what I've done in the past. Should be enough for most WDIS decisions.

Buy Now

30 day money back guarantee!



Includes access to correlated simulations to get advice specific to YOUR matchup.

  • Run the model with 10,000 simulations

  • For people who want the absolute best WDIS advice they can get.

Buy Now

30 day money back guarantee!

30 Day Money Back Guarantee

Try it! If you're not satisified, contact me within 30 days and I'll refund you the purchase price.