Roland Garros WTA: Marta Kostyuk vs Mirra Andreeva

Platform comparison

Active sub-markets

Market context

Marta Kostyuk and Mirra Andreeva are scheduled to meet in the Roland Garros women's draw on 4 June 2026. The market currently prices Kostyuk's advancement at 26% implied probability across Polymarket, where the decimal odds sit around 3.80, compared to roughly 1.30 for Andreeva. Kalshi and Smarkets show marginally tighter spreads on this matchup, with Kalshi's fee structure (0.4% per side) potentially attracting larger position sizes than Polymarket's standard 2% settlement fee, though neither platform has yet achieved Betfair's liquidity depth on clay-court tennis fixtures.

Kostyuk's recent record against top-50 opponents on clay provides the baseline for assessing this probability. The Ukrainian has historically struggled on slower surfaces relative to hard courts, winning roughly 35% of such encounters against seeded players over the past two seasons. Andreeva, by contrast, has demonstrated precocious clay-court performance for her age, reaching quarterfinals at junior level events and posting solid WTA qualifying results. Historical precedent suggests underdogs in this age-and-surface dynamic—where experience gaps matter considerably—typically settle between 20–30% implied probability, placing the current 26% within normal range.

Traders should monitor draw announcements and any late withdrawals affecting seeding, as Roland Garros frequently reshuffles pairings through the first week. Injury reports from both players' recent warm-up tournaments (Strasbourg for Kostyuk, potential tune-up events for Andreeva) will shift probabilities materially. The settlement window extends to 11 June, allowing seven days beyond the scheduled date for completion, though rain delays at Roland Garros typically resolve within 48 hours rather than triggering the 50-50 tie-break clause.

Methodology

This page compares Roland Garros WTA: Marta Kostyuk vs Mirra Andreeva specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to Polymarket Alternative UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). Polymarket Alternative UK routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket Alternative UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on Polymarket Alternative UK?

Zero. Polymarket Alternative UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.