MLB Partners With Polymarket, Tightens Oversight on Betting Integrity

Polygon-based platform Polymarket has become the official ‘prediction market exchange’ of the North American Major League Baseball (MLB) competition alongside a new MLB agreement with the CFTC (Commodity Futures Trading Commission) to maintain the game’s integrity.

One US outlet cited sources that say the deal was worth around US$300 million (AU$423m) over three years for the MLB. It will enable Polymarket to use MLB’s logos, access league data and get brand exposure across MLB’s digital ecosystem and at games. 

In a press release issued on 19 March, MLB shared the news of both deals and talked up the benefits for baseball’s integrity. 

It said a key component of the partnership with Polymarket would be “establishing a comprehensive integrity framework, which includes working together to restrict markets that present an integrity risk to MLB, such as individual pitches, manager decisions, and umpire performance, among others.”

“Polymarket will also integrate integrity controls into its US Rulebook to ensure all of its brokers are held to the same integrity standards,” the MLB said.

Protecting the integrity of the game on the field is our top priority. By engaging in this community, we are able to work together to create clear boundaries with the goal of mitigating risk while providing fan engagement opportunities.

Baseball Commissioner Robert D. Manfred, Jr.

MLB’s memorandum of understanding with the CTFC will provide a framework to “to discuss, cooperate, and exchange information concerning issues of common interest including protecting the integrity of professional baseball and the relating prediction markets.”

CTFC Chair Mike Selig said the partnership would help the regulator “protect our markets from fraud, manipulation, and other abuses.”

Related:Kalshi and Polymarket Each Eye $20B Valuations as Prediction Markets Hit $18B Monthly Volume

Deals Follow Contentious 2025 Baseball Season

The MLB, Polymarket and CTFC deal follows a series of contentious events surrounding betting on MLB games in 2025. 

• The MLB wrote to the CFTC with its concerns about prediction markets offering bets on player props that could be manipulated by people with inside information, and calling for such platforms to have the same ‘integrity’ controls as sports books.
• Two MLB players from the Cleveland Guardians, pitchers Emmanuel Clase and Luis Ortiz, were charged by the US Department of Justice for an alleged scheme to rig bets on pitches thrown during MLB games. They’ll face trial later in 2026. 

Speaking to the New York Times, Polymarket’s president of sports business, Ari Borod, said: “We will work collaboratively with MLB to identify what types of markets pose unreasonable integrity risks for the game of baseball, and try to get those out of the market, with the goal being, how do you protect customers?”

Related: Kalshi Slams Arizona Charges as ‘Overstep’ in Prediction Market Showdown

The legality of euphemistically-titled ‘prediction markets’ is still being determined in the US. Centralised platform Kalshi is currently waging a legal battle with the state of Arizona, where its Attorney General has brought 20 criminal counts against the company for operating an illegal gambling operation.  

Kalshi co-founder Tarek Mansour said the AG’s charges were “baseless and a clear overreach.” He dismissed it as “gamesmanship from a politician who’s up for reelection.”