Methodology
The baseline sets the board. Markets move it.
MarketRank™ starts with the stored Fantasy Baseline from MarketBall's Sleeper player snapshot. MarketBall then analyzes relevant prediction markets for each player, weighing signals by their relevance, market depth, breadth and confidence. When credible market evidence differs from that baseline, MarketRank adjusts the player up or down accordingly — a market-adjusted fantasy ranking built to show where market pricing differs.
The pipeline
From the stored Fantasy Baseline and live market prices to a spot on the MarketRank board.
- 01
The Fantasy Baseline sets the starting order
MarketRank™ starts from the stored player search-rank order in MarketBall's Sleeper player snapshot. Prediction markets don't cover every fantasy-relevant player, so this Fantasy Baseline gives every player a starting position and a reference point for measuring market disagreement. It is not a claim of real-time expert ROS consensus. Team defenses are the exception: their baseline order comes straight from the market.
- 02
We pull live prediction markets
Every few minutes we read fantasy-relevant NFL markets from two venues: the Polymarket Gamma API and the Kalshi Trade API. That covers position points leaders (QB, RB, WR, TE, FLEX, K and D/ST), season stat leaders, statistical thresholds and award markets. We store the current price, 24-hour change, liquidity and traded volume for each outcome.
- 03
We match outcomes to real players
Market outcomes are free-text names. We normalize them (punctuation, suffixes, nicknames, common misspellings) and match them against a Sleeper NFL player snapshot so every contract lands on the right player, team and position.
- 04
We read markets as fantasy signals
A price is a probability, but not every probability says the same thing about fantasy value. 'Top 5 fantasy RB' and a ladder of yardage and touchdown thresholds describe a player's likely season. 'Leads the NFL in rushing touchdowns' describes his ceiling. MarketBall interprets each market for what it actually tells us about expected fantasy value, and weights it accordingly — so an upside market informs a player's outlook without overwhelming it.
- 05
We weight by relevance, depth and breadth
Not all evidence deserves equal say. Deeper, more heavily traded markets carry more weight. Markets that restate the same opinion count once, not five times. A player supported by many independent markets across several categories and both venues moves further than one supported by a single thin contract. Markets that aren't comparable to a player's fantasy role are discounted or excluded.
- 06
The board adjusts — that's MarketRank™
Where credible market evidence differs from the Fantasy Baseline, MarketRank moves the player up or down, by an amount the evidence supports. The result is a market-adjusted fantasy ranking and a 0–100 Market Score. Comparing MarketRank against the Fantasy Baseline produces Market Edge.
One season-long model, two contexts
The frozen MarketRank v1.0 model stays season-long before and during the season.
Draft context
Who should I draft?
ROS MarketRank™ is the board. Season-long markets — fantasy leaders, passing, rushing and receiving yardage and touchdowns, stat leaders, awards, and team outlook — adjust the Fantasy Baseline, and Market Edge (Baseline Rank − MarketRank) surfaces sleepers and fades.
In-Season Mode · active now
What should I do with my team?
ROS MarketRank™ continues to read season-long markets. It powers the ROS board, Market Edge and conditional Buy / Sell / Hold calls, alongside Market Movers and manual My Team roster reads. Weekly rankings, Start / Sit and waiver advice are not currently available.
Markets are weighted in four tiers — direct fantasy markets (season position leaders, top-3 / top-5 / top-10 finishes), season stat leaders, single-stat player props, then awards and game markets as context — and every signal is scaled by relevance, liquidity, volume, recency, and breadth. Books that re-express the same stat (1,000+, 1,250+ and 1,500+ rushing yards) count as one opinion, not three, and no single series can drive more than a third of a player's movement. A $50 market never moves a ranking the way a $100,000 market does, and Market Confidence (HIGH / MEDIUM / LOW) is shown wherever a ranking appears. Healthy historical snapshots support the movement windows shown in the product; degraded refreshes do not replace the ranking. Longer windows currently have fuller coverage on one venue than the other, which is disclosed wherever those views appear.
What the columns mean
The metrics you'll see across the rankings table and player pages.
- MarketRank™
- MarketBall's market-adjusted fantasy ranking. It starts with the Fantasy Baseline and adjusts the board based on what prediction markets are telling us.
- Market Score
- A 0–100 rating of a player's standing on the MarketRank board. Higher is better.
- Fantasy Baseline
- The stored Sleeper player search-rank order MarketRank starts from, and the comparison point for Market Edge. It is not a real-time expert ROS consensus feed.
- Market Edge
- Fantasy Baseline rank minus MarketRank. Positive means market signals support ranking a player higher than the baseline; negative means they support ranking him lower.
- 24H / 7D move
- How many ranking spots a player has gained or lost over that window. Green is up, red is down.
- Signal
- Whether the underlying prediction markets on a player have been moving in his favor or against him lately — bullish, bearish or neutral.
- Confidence
- How much credible evidence sits behind a player's adjustment: how many independent markets, how many categories, how deep, and how concentrated in one venue.
What this is not
MarketBall is a fantasy sports analytics and information service. We read publicly available prediction-market data for analysis only — MarketBall is not a sportsbook, an exchange or a fantasy contest operator, does not accept bets or wagers, and does not let you buy or sell prediction-market contracts. Market Score is MarketBall's proprietary ranking methodology — not a probability that a player will achieve any one specific outcome, and not a promise of fantasy results. Prediction markets can be thin, slow to react to news, or simply wrong: MarketRank is a different signal, not a guaranteed better one. Nothing here is gambling, investment or financial advice. Treat these rankings as one more input alongside your own research.