If you’ve been following my fantasy football posts, you know I run my team off a data set I’ve been building at gridirondata.com. Over the last month or so it went from “an API I use for my own team” to something I’d actually put up against the paid services. My team is 6-3 and in second place overall, though I’m on a two-week losing streak, so the data isn’t magic. I’ve been actively building and adding new features (and users!).
It works inside your AI assistant now
This is the big one. GridIron Data now has a hosted MCP server, so you can connect it to ChatGPT, Claude, Cursor, VS Code, Gemini CLI and a few others. You sign in with your GridIron account and then just ask questions:
- “What are the top 10 RB projections for week 11 in half-PPR?”
- “Any injury news on this player?”
- “Who are the Bears’ starting wide receivers?”
The assistant pulls the answer from live data instead of guessing. There’s a setup guide with a page for each assistant (ChatGPT, Claude, Cursor, Gemini CLI, GitHub Copilot), and it’s listed in the official MCP Registry. I’ve also submitted it to the Claude and Perplexity directories, and the ChatGPT plugin is in review.
This fixed the exact problem I wrote about in week 7, when my AI agent didn’t know Trevor Lawrence and Josh Allen were on bye. It can look that up now.
My own weekly projections
Until now the projections came from outside sources. GridIron now makes its own. They start from public play-by-play data and weather, then blend in sportsbook player prop lines, snap share and a bias correction. On game day they refresh as inactives come out, and they freeze at kickoff.
Every Tuesday a report card grades last week’s projections against what actually happened. If they’re off, you’ll see it.
Injuries within minutes
Injury statuses now update within a couple of minutes of a change, with a daily cross-check against a second source. Pro accounts can get those changes pushed to them by webhook, so you don’t have to keep asking.
Injury and news history is kept for about three years now, which is what made my in-game injury backtest possible.
Betting and prop data
A note first: I don’t condone or support gambling. This section is for people who build their own models and like the numbers, and nothing here is betting advice.
For the people who build their own prop models:
- Player-prop probabilities: give it a stat line and it returns the chance of going over or under, plus fair no-vig odds. It’s a model estimate.
- Per-stat projections, odds on the schedule and defense vs position.
- A usage endpoint with target share and carry share, and box score lines on the stats.
- A Friday post with the week’s usage data for prop modelers, and a guide for pricing props yourself.
More of the data you need on game day
- Depth charts for all 32 teams, with the real starter at every position on offense and defense.
- Official game-day inactives.
- Offensive line injury data, because a missing left tackle matters more than people think.
- Rest-of-season projections, the schedule and bye weeks.
- Lookups by ESPN or NFL player id, so it’s easier to match against other data sets.
- The news desk now follows the top 300 players instead of 150.
Easier to start, easier to pay for
- Sign in with Google or GitHub.
- A free plan that covers player lookups and this week’s projections.
- Yearly billing: Basic is $45 a year and Pro is $249 a year.
- A Pro + Commercial plan ($49 a month or $490 a year) for anyone building a product on the data, with a commercial license.
- An off-season pause, so you’re not paying in March. It picks back up August 1.
- An affiliate program that pays out through Stripe.
Guides and videos
Most of the guides now have a short narrated video walkthrough: start/sit, streaming by matchup history, backtesting projections, pricing props, the trade analyzer and connecting an AI assistant. They’re all on the guides page. There’s also a Python client and a published OpenAPI spec if you’d rather skip straight to code.
You can also follow along on X at @gridirondata_ai. It posts the Friday prop notes and the Wednesday projection grades automatically.
What’s next
Next up is getting ready for the off-season: rookies, the draft and dynasty data, so there’s something useful between February and August.
If you play fantasy football or tinker with sports data, a free account is at gridirondata.com. If you connect it to your AI assistant, let me know what you ask it. That’s where most of my ideas for this have come from.
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