MOIRAI
FAQ
Common questions about Moirai — named for the three Greek Fates who spin, measure and cut the thread of every fight: how the model works, what value bets mean, and what it does and doesn't claim to do.
How does Moirai predict UFC fights?
Moirai is named for the three Greek Fates — Clotho spins the matchup from a fighter's whole career, Lachesis measures each corner's win chance, and Atropos calls how and when the fight ends. Under the hood, an ensemble of gradient-boosted models trained on decades of UFC history weighs dozens of signals per matchup — striking, grappling and control, skill ratings, age and reach, durability and style clashes. The output is then calibrated so a stated probability means exactly what it says: well-calibrated, not just accurate. The exact feature recipe and weights stay in-house.
What is a value bet?
A value bet is one where the model's win probability exceeds the bookmaker's implied probability after vig. If Moirai says a fighter wins 60% of the time and the book is paying 2.0 (implied 50%), the expected value is +20%. Moirai flags such bets, sizes them with a fractional-Kelly stake, and combines them across a card with a convex log-growth optimisation that caps tail loss (CVaR) and per-bet exposure.
How accurate is Moirai?
Moirai is calibrated, which matters more than raw accuracy: when it says 60%, the fighter wins about 60 times in 100. It does not beat the closing moneyline — the sharps are razor-sharp there, so the site flags those bets as low value on purpose. Its real edge is in the prop markets — method of victory, round of finish, total rounds — where the lines are looser and a well-calibrated read shows positive returns in testing across several edge buckets.
What do Conservative, Balanced and Aggressive risk tiers mean?
The risk tier controls how much of the bankroll the portfolio commits and how tightly it caps tail loss. Conservative caps the slate at about 18% of bankroll with a tight CVaR floor and uses single-Kelly stakes. Balanced uses 1.5× Kelly with a 35% slate cap. Aggressive pushes 2.5× Kelly with a 50% slate cap and a looser tail-loss floor, so the slate saturates the cap on rich cards. Stakes are computed by a convex program that maximises log growth subject to those constraints.
What is a calibrated confidence interval?
Each Moirai prediction carries a 90% interval. Calibration means that across many predictions with the same nominal CI, the true outcome falls inside the interval 90% of the time. Moirai uses a locally-weighted split-conformal method so the interval width scales with model uncertainty — confident matchups get tight bands (about ±29%) while pick'em fights get wide bands (about ±67%). The half-width is capped at 0.30 so display intervals never collapse to [0, 1].
Where do the odds come from?
Live odds are scraped from SportsBet every 30 minutes during the week and every minute on fight night, from a Raspberry Pi running a small systemd timer. Closing historical odds for the backtest come from BetOnline. The fight roster comes from ESPN's scoreboard with method, round and statistics backfilled from UFCStats.com. None of these are paid feeds — everything is open data.
How often is the dashboard refreshed?
Predictions, odds and the Top Picks portfolio are rebuilt automatically. The full heavy refresh runs daily at 06:00 UTC and several times on fight-week days; a light ESPN-result poll runs every 5 minutes on fight nights. Results typically land on the dashboard within 60–90 seconds of being posted to ESPN.
Is this betting advice?
No. Moirai is informational. The site is free, takes no affiliate revenue from any sportsbook, and the historical-ROI columns let you judge each market bucket on its own backtested performance. Past performance is not a guarantee of future results. Gamble responsibly. Most jurisdictions require you to be 21 or older to wager; some allow 18+. Set a limit and stick to it.