Arbitrage#004

Sportsbook-to-Polymarket Spread

Major-sport betting lines from big sportsbooks are extremely accurate because huge money keeps them honest, so they act as a reliable 'fair price.' This strategy treats the consensus sportsbook number as the truth and buys or sells the matching Polymarket market whenever Polymarket strays far from it. The edge is simply that Polymarket sports prices lag or overshoot the much sharper book line, and you collect the difference.

What you need to run it

Live feed from 2+ sportsbook odds APIs (e.g., The Odds API)
Conversion script from American/decimal odds to probability
Threshold rules for minimum edge after gas/fees

Where this applies

Markets on Polymarket where sportsbook-to-polymarket spread is the natural play:

Will the Chiefs beat the Eagles this Sunday?
Will Real Madrid beat Barcelona in their next La Liga match?
Will the Lakers beat the Celtics on opening night 2026-27?

Capabilities this demands

Data ingestionCustom code / APILow latency

At a glance

CategoryArbitrage

Requirements3

CapabilitiesData ingestion, Custom code / API, Low latency

VenuePolymarket (CLOB, Polygon)

Build it

Related arbitrage strategies

This is documentation, not advice. Poly Research & Robotics publishes how these strategies work because the method should be checkable — not as a recommendation to trade them. See the full strategy database (147 strategies) or the data resources directory.