Resolution criteria on PolyGram: This market refers to the doubles tennis match between Maric/Mikrut and Grevelius/Heinonen in the Zagreb, originally scheduled for May 14, 2026 at 4:00AM ET. This market will resolve to 'Maric/Mikrut' if the team of Maric/Mikrut advances against Grevelius/Heinonen. This market will resolve to 'Grevelius/Heinonen' if the team of Grevelius/Heinonen advances against Maric/Mikrut. If the match is canceled (not played at all), ends in a tie, or is delayed beyond 7 days from the scheduled date without a winner determined, this market will resolve to 50-50.
PolyGram is an on-chain prediction market where you trade YES or NO outcome shares with real USDC on Polygon. For this market, buy YES if you believe the event will happen, or NO if you think it won't. Your maximum loss is your stake — winning shares pay $1.00 each at resolution. Unlike sportsbooks, there is no house edge: prices are set by supply and demand from other traders and reflect the crowd's real-time probability.
Market outcomes
| Zagreb (Doubles): Maric/Mikrut vs Grevelius/Heinonen | 19% YES | 81% NO |
| Completed Match | 50% YES | 50% NO |
The Zagreb doubles draw will feature the pairing of Maric and Mikrut against Grevelius and Heinonen in what is scheduled as a second-round encounter at the ATP 250 event. The market currently reflects a 19% implied probability for Maric/Mikrut's advancement, suggesting the order book favours their opponents. This probability formation occurs ahead of the 14 May fixture, with settlement contingent on a decisive result by 21 May 2026.
Maric and Mikrut represent a partnership with limited recent ATP doubles pedigree, whilst Grevelius and Heinonen have shown greater consistency on the secondary tour circuit. Historical patterns in lower-tier ATP doubles suggest that seeding and ranking differential typically correlate with match outcomes, though upsets remain frequent enough that 19% probability for the underdog pairing reflects plausible odds rather than dismissal. The current Polymarket order book pricing suggests traders view the favourites as materially stronger, though the absence of recent head-to-head data between these specific pairings limits predictive certainty.
Key variables for traders include confirmation of player fitness and participation status as the event approaches, any late withdrawals or substitutions that might alter the competitive balance, and court conditions at the Zagreb venue which can favour aggressive or defensive doubles styles. The settlement window extends to 8 May UTC, providing a week beyond the scheduled date for match completion. Any cancellation, tie result, or delay exceeding seven days triggers a 50-50 resolution, introducing tail-risk considerations for positions held through the event window.
This market settles from the official outcome published at https://www.atptour.com/en/scores/current. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.
The mechanics for trading "Zagreb (Doubles): Maric/Mikrut vs Grevelius/Heinonen" are the same as any other PolyGram event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.
$5 in lifetime turnover and $172 of resting liquidity puts this market in the below the median by volume for tennis contracts on PolyGram. Order-book depth is thin — large orders may need to be split across the book or executed as limit orders.
Last 24 hours alone saw $5 in turnover, well above the lifetime daily-average for this market — a clear sign of news catalysing trader activity right now.
The market has been open for under a month — fresh enough that information asymmetry remains a real factor.
Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.
Resolution is sourced from https://www.atptour.com/en/scores/current. Settlement is executed by the UMA optimistic oracle on Polygon, with a 2-hour dispute window before payouts clear.
This prediction market is scheduled to close on 21 May 2026. After the resolving event occurs, settlement typically clears within 24 hours once the UMA optimistic oracle confirms the outcome. All payouts are in USDC on the Polygon network.
To trade on this prediction market, create a free PolyGram account at polygram.ink, deposit USDC via Polygon, and place a YES or NO order on the outcome you believe in. You can learn more on our how-it-works page. Your maximum loss is limited to your stake — there is no leverage or margin.
When the outcome is determined, winning YES shares pay out $1.00 each in USDC, while losing shares pay $0. Settlement is handled by the UMA optimistic oracle on Polygon — a proposer submits the result, a two-hour dispute window opens, and if uncontested, payouts are distributed automatically. You can withdraw your winnings to any Polygon wallet.
Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose.
Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.
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