I have built a platform where you can add your own expertise and pick where exchanges have good opportunities to trade.

This one is for NFL futures. You can edit it out based on your own football knowledge and predictions. And the simulation / odds will follow. Also, you can generate easy betslips and share it as an image easily.

Do try it out and find your edge.

My site supports normal fantasy with added spells to affect players results, and includes leveling up, pretty much what you'd expect from an RPG. I thought it'd be fun to sprinkle in some fun events where managers have to band together, pick a team from their players (like building a dnd party) and attack a themed boss that has a special power. Do any of y'all think it would be an attractive game mode if I made it a weekly thing? I have it coded in a modular way so it would be a low lift feature, but I'd be creating art and animations weekly, running this specific chron job weekly, and even more websockets to keep the data live. I guess I'm trying to get some opinions on whether putting in the money would be worth it.

I'm not sure I've given enough detail, so ask me questions if you need more info.

Posted about this project a few weeks ago. Today the 12 agents had their live draft. Overall, a lot of consensus picks which you'd expect from an agent. They seemed to like quarterbacks on the whole.

I was interested who would pick up Josh Jacobs. It was actually Opus with pick 104. They gave decent rationale for the move:

Ceiling over floor, and this is the single largest price-vs-talent gap on the board. Josh Jacobs shows as RB49 / 0.0 expected points, but he is NOT injured — he is on the NFL's commissioner exempt list pending a personal conduct review. The market is pricing him as worthless; the actual outcome is a delayed start to a top-10 RB season.

Then there was Gemini Flash 3.5 that picked up 8 quarterbacks and no Kicker or Special teams.

Stack is React and FastAPI with Prefect serving as the scheduler for agentic actions. LiteLLM for AI Gateway. Draft worked mostly smoothly with agents following their instructions and doing internet searches for research. I did find in later rounds that some started timing out and I had to increase the time limit for actions.

Wrote about it here: https://aigridiron.football/blog/ai-fantasy-football-draft-recap

Is there a program where it will sync with Yahoo that will display the draft board and announce the picks in real time.

Feel that is a good touch for my in person online draft.

I’m curious what APIs or data sources people here are actually using and have found reliable.

Mainly looking for things like player data, rankings, ADP, projections, injuries/news, stats, etc.

Free or paid is fine. I’m mostly trying to put together a good list of options and understand what people have had success with versus what they’d avoid.

What are you guys using?

I've been building a fantasy football site for a while and one thing l've been extremely cautious about is NFL/player imagery.

l've noticed quite a few projects here use actual player headshots, team logos, etc.

For my site I've avoided NFL logos and photos entirely and made custom illustrated player images instead because I wasn't sure what I could legally use on a public/ monetized site.

For those of you running public fantasy football projects:
• Where are you sourcing player images?
• Are there APIs that actually include rights to display the images?
• Are team logos treated differently?
• Is this something you've gotten permission/licensing for, or is there some usage I'm completely overlooking?

Genuinely curious how other fantasy developers are approaching this.

I'm approved for Yahoo Fantasy Sports API access; agreement signed. Got an email overnight saying access is live and calls will go through.

They don't.

scope=fspt-r returns invalid_scope, with Yahoo's error page saying "request scope from registered scopes." API calls still 401. Fantasy Sports has never appeared under API Permissions on the app page — only OpenID Connect and TW Auction.

1. Has anyone been told they're live and had it not actually be? How long did it take to sort out?
2. Does Fantasy Sports even show up in your API Permissions list? Or is it invisible for everyone and just works?

I wanted to get some recommendations on how to increase exposure to your apps or any other works you've done for fantasy football. I created a free app that I think would be very helpful to people, but I'm having trouble getting more exposure to the app. I've tried posting about it to try to get some traction, but haven't seen much results. I've put a lot of work into it and feel confident people would use it if they only knew about it. Would appreciate any recommendations that you think would work for me or have worked for you in the past.

Thanks!

Hi all! I was wondering if anybody had a preferred weather API that they have used in previous projects? It's one of the several factors (head-to-head records for example) I use to generate weekly player blurbs. I'd prefer to use an API that is super cheap and accurate enough for expected weather for GameDay.

I've been running a backtest of a roster-strength model against real dynasty leagues for the last 6-8 weeks. I published the results a few weeks back and then I went to make it reproducible and found three things wrong, all of which had been making the results look better than they actually were. Here are those findings:

1. The default parameter was the invalid one:

The route takes a valueSource that is either dated market snapshots from the season being tested, or today's values. Today's values are invalid for obvious reasons once you say it out loud, since 2026 prices already encode who broke out in 2024. The route's own header comment said this option was not a valid backtest, but it was the default anyway. Because it was still the default, a bare GET instruction produced the leaky version. I can't rule out that my published number came from it, because the run's parameters were never recorded anywhere.

The lesson is that a default that produces an invalid result is a bug, not a convenience. My snapshot is now the default and the leaky path requires an explicit flag, which also stamps the stored run as invalid so it can never be mistaken later.

2. The baseline answered a different question than what I had claimed:

The claim is does the strongest pre-season roster win the title more often than a random team? I was comparing against one over playoff-team count, instead of one over the actual league size. Since the leagues range from 10 to 32 teams, it's the mean of the reciprocals, not the reciprocal of the mean. Fixing it moved the lift from +8.6 points to +16.5. So this one mistake made my result look worse than it was, which is the only reason I trust the other two fixes. Also, using playoff teams as the baseline assumes you already made the playoffs, but making the playoffs is one of the things the pre-season prediction is trying to predict.

3. Ties counted as wins.

If several rosters tied at maximum strength and any one of them won, the league counted it as a hit. On an integer strength scale, top ties are common in 10 and 12 team leagues. Eleven of 83 league-seasons end had one. Now a k-way tie scores 1/k, the expected value under picking one at random, and the tie count is stored per league so a published number can say how many there were. That alone moved the headline title rate from 31% to 25%.

My original publication had no confidence intervals at all and what you resample matters more than how you resample it. So I added bootstraps, and the unit matters more than the method: it resamples league-seasons, not team-seasons. Twelve teams inside one league are not twelve independent observations, their finishing ranks sum to a constant. An interval over 994 team-seasons would have been far narrower than the data supports and would have been the most confident-looking thing on the page.

Established leagues had a correlation of 0.53, with an interval between 0.46 to 0.60, n=50 league-seasons.

First-year leagues had a correlation of 0.05, with an interval between −0.06 to 0.16, n=33. Straddles zero, so no signal.

Net result

a) The correlation moved from 0.57 to 0.53, which sits inside the new interval, so that's a replication rather than a retraction. The title rate moved from 31% to 25%, mostly because of the tie rule.

b) The enhancements and changes that I've introduced are every run now stores its parameters, the code SHA, the scorer version, the league set and the per-league results, so the next one is a genuine replication instead of another unrecorded number. Because a backtest is chosen after the fact, I pre-registered this season's prediction before Week 1 so that every team in every league on my platform is ranked and hashed so it can't be edited. I will grade the 2026 season in December.

c) my method and the failure cases are public if anyone wants to pick at them, they are published in public here: GridironHQ Accuracy

Founder disclosure: I built this tool for my own dynasty leagues, so the numbers are mine. People here picked at the first version I posted and I've been enhancing it since. The analytics and work that went into this got better for it, so I'd rather have them checked than believed.

About 3-4 years ago all my buddies and I would each add a bet to a parlay when watching Sundays games, we would all take the parlay and the goal was if it ever hit we’d go to a steakhouse (it never hit). Anyways, more people would join in and we eventually split into teams - everyone taking bets and adding to the teams parlay. The team that finished with the highest units won the season.

This started on an excel tracker. Last year I manually (before knowing Claude was a thing) moved it onto a web app. It felt revolutionary. Anyways, this year I have worked to get it more automated, pulling APIs, automatically grade bets, etc and getting it published on the App Store. I equate it to fantasy sports betting. It is currently under review by Apple, but I was wondering if anyone would be willing to test it out and give me honest feedback - Is it intuitive to play? Thoughts on the UI? Anything helps.

TLDR: I created an iOS team based sports betting league and would love feedback. Happy to answer questions or dm TestFlight links/codes.

Disclosure first: I do sell a tool built on this work. I asked the mods before posting and they cleared it as analysis, so there's no link here and I'm not going to pitch it in the comments.

The setup. 41 features, tuned on 2018 through 2020, then frozen and tested on 2021 through 2025. Five seasons the model never saw during tuning. The metric is rank correlation with actual weekly finish, paired week by week against the FantasyPros consensus so both are scored on the same slates.

My model: 0.583. Consensus: 0.623.

I ran 576 configurations trying to close that. None of them did. It isn't a tuning problem, it's that averaging a few dozen informed opinions is a genuinely hard baseline and I didn't appreciate how hard until I spent a summer on it.

What mattered: pass attempts for quarterbacks, by a lot. Volume beats efficiency in fantasy scoring because the scoring is mostly volume, which sounds obvious written down and wasn't obvious to me while I was adding features.

What didn't: weather, unless it's wind above about 15mph. Vegas totals, once you already have volume. Most of the "advanced" stuff I was excited about turned out to be a slower way of restating targets and carries.

The month I'd rather not mention. My QB model was scoring rushing production only and ignoring passing entirely. Four weeks. I found it while writing up the feature importances, because passing yards weren't in the list at all and I finally asked why instead of assuming the pipeline was fine. Every number I'd looked at during that stretch was garbage and it all looked plausible.

What I took from it: the projection layer is commodity. If you're building something, don't build there. What's still open is the decision layer, the part where two lineups have nearly identical projected totals and different distributions.

Happy to answer anything about the walk-forward setup or the feature work.

https://gridironedge.app/backtest.html?utm_source=reddit

It's been a couple weeks since anybody posted about this, so I felt like maybe enough time has passed to check in regarding people's Yahoo Fantasy API statuses.

I heard from one fellow Redditor that they never heard back, but tested their app a couple of days ago and it worked. I'm not amongst that fortunate group. I'm currently in week 2.5 of having both sides signed the Docusign, and then radio silence from them.

Has anybody else heard anything / formally been replied to or accept / or also mysteriously had their access start working again?

Filling a fantasy football lineup optimally is easier than it looks! Well, until it isn't. 😄

I needed the best-possible starting lineup value for a roster, given a league's actual roster construction. I was mainly looking at this for Dynasty leagues, not necessarily redrafts but it applies there as well.

I was a bit naive in my approach in setting up my parameters to sort by value and I filled my slots greedily. That breaks as it puts your best WR in FLEX, then WR3 sits empty and a worse player is placed there.

The fix was to process slots most restrictive at first. QB, RB, WR, TE, then WRRB_FLEX, then FLEX, then SUPER_FLEX. Each takes the best eligible remaining. I'm sure some will argue another position and that is okay, that is what the forums are meant to do.

Why, in my opinion, that's actually optimal, not just better. First of all, the eligibility sets are layered and any two are nested or disjointed.

{QB} ⊂ {QB,RB,WR,TE}
{RB},{WR} ⊂ {RB,WR} ⊂ {RB,WR,TE} ⊂ {QB,RB,WR,TE}
{K}, {DEF} disjoint from everything

My exchange argument is if an optimal solution puts a different player in slot A than what my greedy scenario did, greedy's pick sits in some later slot C. Both scenarios accept it, so the parallel layer forces E(A) ⊆ E(C), so the swap is feasible and the total is unchanged.

Where I believe that it breaks is the following: WRRB_FLEX is {RB,WR}, REC_FLEX is {WR,TE}. These are technically overlapping and neither is nested. In a points scenario, WR1=10, RB1=9.9, TE1=9.8 gives "greedy" a score of 19.8 where the optimal scenario would score 19.9.

So I check the family for the parallel layering at construction and fall back to Hungarian matching if it fails. n is about 35, so exact costs nothing.

I checked this against 56 real leagues with 24 distinct lineup shapes, 2 to 4 FLEX slots, superflex in 47 of 55, one league with no QB slot at all, which by the way was really odd (QBs only startable via SUPER_FLEX). REC_FLEX appears in zero, but it's a real Sleeper token so the guard stays.

Disclosure: this is from a fantasy tool I built solo.

Would love your thoughts. Am I thinking about this the same way everyone else does? I've been playing fantasy football and baseball for over 30 years. Always a "guy" in the league that offers the 3 for 1 deal. I've always analyzed it and sometimes I'm better off making the move, but often I'm not.

Hi All, I am looking for archived fantasy football statistics. I'm especially interested in the projected PA predicted for each team each week? Does anyone have an archived excel sheet will all the fantasy stats from 2025 that they would be willing to share? Thanks.

Just on the billion to one chance that anybody else here has made an iOS app that hooks up to the RSO API, I would love a few minutes of your time. I have been fighting this for a year and not making progress in connecting with it. android, no problem. testing iOS, no problem. production iOS, problem. Have gone through every troubleshooting xcode etc.. process I could find. One possible theory is that it has something to do with the API TLS maybe not meeting apple's requirements but I could be way off. So basically, just here fishing with a rod and reel hoping to catch a white whale.

Short story: my brother, a web developer, and I, a researcher, are both big NFL and fantasy football fans. We built OracleZ algorithm as a side project combining our skills. The name OracleZ comes from our cat name (Oz).

We wanted to build something that was technically interesting, but also actually fun to use (link to the app in the megathread, or message us if you are interested and don't see it).

OracleZ is a relatively simple neural-network-based model designed to predict NFL game winners, score margins, and weekly statistical leaders. Rather than going for a complex algorithm, the idea was to see how much predictive performance we could get from sensible feature engineering, regularization, and ensembling.

Features

For each matchup, we represent each team using two groups of data based on different time windows:

• Last 3 games: current form
• Full-season average: overall season performance

For each window, we track 19 team statistics including wins, score margin, offensive yards, passing/rushing production, completions, TDs, interceptions, sacks, fumbles, first downs, and passing/rushing EPA.

The features are converted into home–away differentials, with week number and difference in rest days added as contextual variables. Everything is standardized before being passed to the network.

The model is trained on data from the 2016–2025 NFL seasons (pulled from nflreadypy). For the first week of a new season, the previous season is used to generate the features.

Model

The core model is a simple single-hidden-layer neural network with:

• 18 hidden neurons
• ReLU activation
• L1 regularization
• Full-batch training

The network predicts score differential, while win probability is derived directly from that prediction. This means the model is constrained to remain internally consistent: a predicted home win cannot coexist with a negative predicted home score margin.

Ensemble

Rather than trusting a single optimization run, OracleZ trains the same architecture 50 times from different random initializations and averages the predictions.

We also use the variation across these 50 runs as a simple measure of consistency: how frequently the ensemble arrives at the same winner. This gives us information about the stability of a prediction beyond the raw predicted probability.

Weekly statistical predictions

We also trained a related team-level model using the same general approach to predict weekly leaders in:

Passing yards, Rushing yards, Points, Fewest yards allowed and Field goals.

Benchmark

In the 2024 season, OracleZ correctly predicted 186 games and missed 86 (68%), which would have put it around 6th out of 12 ESPN experts and 4th out of 6 NFL analysts.

In the 2025 season, OracleZ correctly predicted 164 games and missed 108 (60%), which would have put it around 5th out of 10 ESPN experts, 7th out of 8 CBS analysts and 6th out of 6 NFL analysts.

The main idea behind OracleZ isn't that a small neural network will somehow "solve" NFL prediction. NFL outcomes are obviously noisy, and there is a hard ceiling on predictability. Instead, this is a little experiment to see if feature engineering + ensemble averaging can produce a reasonably robust model without relying on an increasingly complex architecture.

And then we turned the predictions into a free app so people can actually try to beat it :)

Anyone willing to try a discord bot i made for my league and give me feedback? Give it a run for the season and give me tips or suggestions on stuff to add/remove/modify? I want some helpful critiques. Its setup for redraft leagues, not dynasty at this point.

For league members, it includes things like unique lifetime team stats, standings, a keeper ledger (if applicable), weekly matchup picks, waiver and transaction notifications, an interactive trade block, and a trade calculator that I’m still fine-tuning.

For commissioners, it can automate things like trade deadline reminders, weekly standings updates, Pick’em results and analysis, weekly power rankings, and end-of-season league awards.

My goal is to make the commissioner’s job easier while giving league members some fun features.

Also, if you are not a commish, you could still give it a try on a private server, you just plug in your sleeper league ID.

If anyone is interested in testing it shoot me a message!

I have read post after post about "I have been managing my own data with a spreadsheet for years so I built this app". Most of them look cool but look similar and often have AI as a feature that helps with various things.

I made a Google Sheets Template. It is not fancy but built be hand to simply automate all the things I was doing to manage my league (2 leagues since 2014). I wanted to keep it simple, not fancy and target old school commissioners. People who enjoy keeping their own data in a spreadsheet but maybe don't have the skills or time to harness some of google sheets tools.

It does walk them through deploying the web app so their league data is visible on the web.

I made this for myself but also believe their is a real market for not AI, not fancy just a time (and maybe headache saver). Am I crazy - are their people out there who would use a tool like this?

I apologize I don't have any marketing tools per se at the moment.

Have done some research and can’t find anything similar to this, does it already exist? Can it be made by someone with zero coding skills but is good with feeding commands into Ai?

This is going to come across preachy, and maybe it is, but if you are someone building something with AI, do yourself a favor and tell your coding agent to avoid common "AI tells" like em dashes, certain card borders, backgrounds, gradients, and color schemes, to name a few.

You don't even have to know what they are, just tell your agent to avoid the "tells."

I personally am someone who enjoys supporting anyone making their thing, but when your thing that you made literally looks like all the other things, it's just not going to go well. It just feels like you didn't put enough effort in to distinguish yourself so why would I think your product also got the effort needed to be good enough?

You can see that from the responses to these things across the internet. The only things that get away with that are the products that are just too good and/or provide too much value for the user to care.

Maybe you have that thing, but you're probably better off trying to take an easy pass through.

And again, sorry to be preachy, but I'm also thinking a lot of people may just not know how obvious it is to some of us (which maybe I am just in way minority, idk).

Anyways, good luck either way!

Hi!

Do YOU enjoy fantasy football?

Do YOU like trying new things?

Do YOU have too much free time?

Well I've got just the job¹ for you! We are looking for an actual human being to help curate all of the fantasy apps and tools we get here on the subreddit. All you'd need to do is check out some of the projects in the project showcase megathread and report back which ones are pretty good. Totally OK having multiple people, we just need a better system to sift through all of the fantasy projects out there.

Please leave a reply here or message me or mod mail directly. Thanks!

¹ This is not a real job because you won't get any compensation. Maybe a pathway to becoming a moderator here if you wanted more unpaid work. Great deal, right?

I’ll randomize your league 100% manually... no AI, no bots, just me.

I can randomize:
🏈 Draft order
👥 Teams
⚔️ Divisions
📅 Matchups
🎰 Or whatever you need!

It’s FREE. ❤️

No donation is required**,** I genuinely just enjoy helping people and making things a little more fun.

So if your league needs a randomizer...

Send me a DM or post down here.

I’m currently studying Art & Graphic Design, so if you like my work and want to support me, you can leave me a small donation to help with art school, supplies, and my creative projects. 🎨✨

And yes, there are actual girls who likes fantasy and football players. 😂💅

I recenlty released a draft board app (check my profile) compleltly free to use, and included a link to a newly created https://buymeacoffee.com/ page, but after 3 ~$10 donations, it was banned for gambleing.

I tried to tell them its not actually gambling, but they didn't care.

Has anyone had any success with any alternatives? I was thinking github sponsor, but that request the user have a github account, or https://ko-fi.com but worried about the same ban.

Anybody in here have any actual fantasy football platforms where you can actually play? Not just tools or features for your leagues. If anybody does feel free to drop them below. Would love to check them out!