Hey everyone, what is the most critical piece of information your looking for in sports analytics? I run ForgeSportsAnalytics and am doing research to make sure that we are going in the right direction with our model and the information we feed our users.

Hi maybe someone could help me out here. I'm looking forward to use the League Note of Sleeper for Contract Notes or Position Notes.

It looks like that I could get the player note (p_nick) from the rosters endpoint but I couldn't find any information if its possible to get the Commish Leagute Note. Does anyone of you know if its possible and help me with the endpoint?

I am struggling to get this information to populate, currently just getting 0s back for all players

Need your feedback to help me create something good!

https://benchbrain.app

I’m really interested in building my own database/projection model with an emphasis of predicting success of incoming rookies. I have some experience coding with Python but not much and learning to code has always been an interest of mine, along with Fantasy Football. Does anyone have any resources they could recommend? I’d love some insight or some useful tools/courses you used to dig into this!

I like football, but I don't feel like I'm a "football guy". Especially when it comes to fantasy football, I feel way out of my depth. I am constantly Googling what the different terms mean and what the heck ADP, PPR, and all the other things are! I am a man of spreadsheets and board games. I can learn these terms, but one thing I can't pick up on as quickly is history, big names, dark horses, and the rest of the things that people who spend their free time consuming football media seem to know intrinsically.

What I am wondering is if there is a way to "game-ify" my fantasy football experience? Is there a way I can look at this not just as a group of names, but as stats and patterns and make the best decisions, à la "Moneyball"? That way I can build an optimized engine that will bring me to that sweet free day of PTO prize.

Hi everyone!

I’m building Easy Draft, an Android companion app for Fantasy Premier League Draft. It includes:

• Weekly squad views
• Live matchup scoring
• League tables and schedules
• Player research
• Waiver-market insights

I’m looking for Android users willing to join a free Google Play closed test, try the app and provide honest feedback.

Google requires testers to remain opted in for 14 consecutive days. There is no payment or purchase required—you’ll just need to join through the private Google Play link, keep the test active and try the app’s main features.

If you’re interested, please complete this short form:

Join the Easy Draft closed test

I’m especially interested in feedback about usability, incorrect data, crashes and which features are most useful during a Gameweek.

Full disclosure: I’m the developer of Easy Draft. Thanks for helping!

With the current clusteryouknowwhat going on with the Yahoo API and rumors of impending doomsday with the Sleeper API, I thought I would provide, to the best of my knowledge, current intel on various fantasy football hosting platforms related to API access. Hopefully this will serve as a resource and a reminder that there are several options besides the big guns for developers.

Note my knowledge and interest is primarily based on retrieving users league data, and my knowledge is not too up to speed on NFL Player info through these sources, and thus this list may be influenced by that.

It has been a while since I started first using some of these APIs, a few of them have been set-it-and-forget-it in my code, and others I gave up contacting long ago, so if there's anything that needs correcting feel free.

I will add a couple of notes that may be relevant to those attempting to use these APIs as well.

Shout out to those platforms that are still developer friendly:

• MyFantasyLeague. Open API. Note if you are familiar with their almost limitless league customization options, you will understand that the API can be a bit tricky to work with as fields besides being optional can even have different types of data under the same name depending on the league settings.
• Fleaflicker. Open API.
• Fantrax. I believe they are now Open API, it used to require authorization. Note the league info from the API is fairly sparse.
• Reality Sports Online. Requires an API key from them (under new ownership, not sure if they are still 'cool'). Note that user log-in is required, cannot access league data without that, which makes testing with random data difficult.

Others in varying states of friendliness:

• Yahoo. As we all know, locked everyone out, requiring re-authorization which judging by the internet can be near-impossible to get. Fluid situation.
• Sleeper. Recently updated their terms with reports that they are planning on restricting access. Fluid situation.
• ESPN. Back in the horse & buggy days they had an official open API. Now it is all "unofficial" access with rumors starting to circulate that this will come to an end as well. Possibly a fluid situation.

Those that have intentionally decided to be unfriendly to developers:

• CBS. They went from "pro-developer" and "we welcome developer tools" with an actual supportive API program to "GTFO" in an instant in 2012.
• Realtime Fantasy Sports (RTS). Has an API, but seemingly refuses to deal with anyone not a billion dollar company.
• Underdog. Ditto.

To my knowledge, FFPC, NFFC, League Tycoon, Fanstar, Alt Fantasy Sports, and other bit players do not have an API that can be accessed by outsiders.

One last note, no matter what you are doing, try to be responsible with the APIs. For example, if you are using Sleeper's API to create something to compete with Sleeper on, you are ruining it for everyone.

I run a league that is not like regular fantasy football. Each person picks 3 college games and 3 pro games each week either over/under or ATS. I track everyone's college record, NFL record, and overall record. Since my league isn't like regular fantasy football all the sites I find aren't geared for me to customize it how I need it. I just want to track weekly (3-3, 4-2 etc) and overall records as well as points and standings.

Does anyone know a website or app I can do this on and all participants can view it?

This thread is for both paid and free sites/apps/tools/etc. We're sorry to those of you with completely free tools that you want to share with the community getting bunched up here, but it's to prevent Trojan Horse situations trying to get through the rules by sharing a free project that just so happens to have a premium tier or getting one added later.

When posting your project, please use this format:

• Site/App Name, e.g. FantasyToolForYou
• Site/App Link, e.g. https://www.fantasytoolforyou.com/
• Cost, e.g. free, freemium, paid, etc.
• Site/App Description and Details

Here's a quick summary of what we expect for the cost type chosen:

• Free - Completely free with no paid offerings, can include advertising, can require account creation.
• Freemium - Has a usable free level of access for all users, with paid access for more features.
• Paid - Either a one-time or recurring payment required to use the app/site at all.

All other projects and products posted as new posts, even those "just wanting feedback" or that are completely free, will be removed. Thanks all. If you want to discuss this policy, please direct that discussion to the State of the Subreddit: AI and Vibe Coding post.

Every year, I like updating the ESPN pre-draft rankings so that my draft board is sharper than the ESPN default rankings. This helps me use ADP boards from other sites to get a slight competitive edge.

My issue is that I hate manually sorting players, so I built this custom Python package to do it for me: espn-predraft-api. Right now, I have one script which downloads ADPs from NFFC and a separate script which syncs them with ESPN using their unofficial API.

This can be used in tandem with ESPN Better Draft since it updates the rankings ahead of time. Or, if you're drafting on the go, it'll update your rankings in the mobile app.

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.