TennisEdge's AI model finds no betting value in S. Costoulas vs T. Mrdeza (French Open on 2026-05-18) — the market is efficient, with S. Costoulas favoured at 1.01.
Independent estimates of who wins, each from a different method. The blend is what the bot prices against the market.
| Method | S. Costoulas | T. Mrdeza |
|---|---|---|
| Elo ratings-based, surface-weighted |
69.2% | 30.8% |
| Machine learning 29-feature gradient-boosted model |
88.1% | 11.9% |
| Blend what the bot actually prices off |
78.7% | 21.3% |
| Market implied de-vigged from the opening odds |
92.4% | 7.6% |
We publish how well these score against the closing market, including where they lose: how accurate are tennis predictions?
| Player | Surface | Elo | Record | Matches |
|---|---|---|---|---|
| S. Costoulas | hard | 1570 | 131–79 | 210 |
| T. Mrdeza | clay | 1298 | 26–26 | 52 |
Our own ratings, computed from match results since 2018. Players with fewer than 5 rated matches are omitted rather than shown at a provisional starting value. Last updated Aug. 4, 2026.
S. Costoulas leads 1–0 over 1 meeting. Full record.
| Date | Event | Surface | Winner | Score |
|---|---|---|---|---|
| May 18, 2026 | French Open | clay | S. Costoulas | 2 - 0 |
| L | G. Knutson | 2 - 0 | Aug. 4, 2026 |
| L | M. Inglis | 0 - 2 | July 29, 2026 |
| W | L. Cabrera | 0 - 2 | July 29, 2026 |
| L | A. Aksu | 2 - 1 | July 20, 2026 |
| W | A. Aksu | 2 - 0 | July 19, 2026 |
| L | S. Costoulas | 2 - 0 | May 18, 2026 |
| L | T. Kostovic | 0 - 2 | Jan. 12, 2026 |
| L | V. Grammatikopoulou | 2 - 0 | Jan. 24, 2023 |
| L | K. Deichmann | 1 - 2 | March 30, 2022 |
| W | M. Di Giuseppe | 0 - 2 | March 29, 2022 |
All May 18, 2026 results & picks →
Math-only prediction: no LLM calls used