Projections derived from live betting markets — not expert opinions. Auto-draft engine, win-probability glasses, anti-mistake protection. The full POSEIDON probabilistic stack applied to NFL, NBA, MLB, and Soccer.
A 15-minute interactive walkthrough. Draft a team using actual ADP data, watch the season play out week-by-week with real player outcomes, see exactly which decisions cost you — and what you should have done. Available for all four sports. Shareable. No signup required.
Other sites tell you "22.4 points." We show the full distribution: floor, median, ceiling, boom percentage, bust percentage. Interactive violin plots per player per week.
Six strategies (Balanced, Boom/Bust, Zero-RB, Hero-RB, Stack-Heavy, Late-Round QB). Lock any picks; engine recalculates the rest with cinematic animations.
Six systems that catch your common errors: tilt detector, insurance detector, recency bias alarm, stale ranking detector, rule audit, bye-week pre-warner.
Every decision shows real-time probability impact. Start/sit, trade, waiver — see exactly how your matchup win chance shifts. Monte Carlo–backed.
Edge-distributed architecture means no single point of failure. While ESPN's API hits limits on opening weekend, we don't.
Don't just see if a trade helps you. See whether the OTHER manager will accept. Monte Carlo on their roster needs and behavior patterns.
When the fantasy model is validated, its walk-forward record publishes here in the open — POSEIDON vs ESPN vs Yahoo vs FantasyPros. Until we've earned a number, we won't claim one.
Sync ESPN, Yahoo, Sleeper, CBS, NFL.com. Cross-league conflict detection. Live Sunday Hub. Personal RedZone for fantasy.
Replay any past season with your decisions. See what would have happened if you'd done X instead. The clearest fantasy tutorial anywhere.
POSEIDON vs the field · Updated 2026-05-22
| Feature | POSEIDON | ESPN | Yahoo | Sleeper | FantasyPros |
|---|---|---|---|---|---|
| Probability distributions per player | YES | No | No | No | No |
| Projections from live betting markets | YES | No | No | No | No |
| Auto-draft with partial lock | YES | No | No | No | Yes |
| Anti-mistake protection | YES | No | No | No | No |
| Trade acceptance predictor | YES | No | No | No | No |
| Multi-league dashboard | YES | No | No | No | Yes |
| Commits to a public, validated accuracy record | YES | No | No | No | No |
| 4-sport coverage | YES | Yes | Yes | Yes | Yes |
| Free forever (no paywall) | YES | No* | No* | Yes | No |
| Never crashes on Sundays | YES | No | No | Mostly | N/A |
Every math feature is free forever. Persistence, multi-league sync, and the social layer become available with a free membership. Create an account when you're ready — no card required.