TennisEdge's AI model finds no betting value in C. Gauff vs S. Sierra (Rome on 2026-05-09) — the market is efficient, with C. Gauff favoured at 1.10.
Independent estimates of who wins, each from a different method. The blend is what the bot prices against the market.
| Method | C. Gauff | S. Sierra |
|---|---|---|
| Elo ratings-based, surface-weighted |
47.0% | 53.0% |
| Machine learning 29-feature gradient-boosted model |
38.8% | 61.2% |
| Serve / return point-by-point simulation |
33.2% | 66.8% |
| Blend what the bot actually prices off |
39.7% | 60.3% |
| Market implied de-vigged from the opening odds |
86.4% | 13.6% |
We publish how well these score against the closing market, including where they lose: how accurate are tennis predictions?
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 March 28, 2026.
C. Gauff leads 3–0 over 3 meetings. Full record.
| Date | Event | Surface | Winner | Score |
|---|---|---|---|---|
| July 1, 2026 | Wimbledon | grass | C. Gauff | 2 - 1 |
| May 9, 2026 | Rome | clay | C. Gauff | 2 - 1 |
| Jan. 3, 2026 | WTA United Cup | hard | C. Gauff | 2 - 0 |
| L | K. Muchova | 2 - 1 | July 9, 2026 |
| W | J. Pegula | 1 - 2 | July 7, 2026 |
| W | B. Bencic | 1 - 2 | July 5, 2026 |
| W | C. Liu | 1 - 2 | July 3, 2026 |
| W | S. Sierra | 1 - 2 | July 1, 2026 |
| L | S. Stephens | 0 - 2 | Aug. 4, 2026 |
| L | T. Prozorova | 1 - 2 | July 27, 2026 |
| L | C. Gauff | 1 - 2 | July 1, 2026 |
| W | A. Bondar | 2 - 1 | June 29, 2026 |
| L | Q. Zheng | 1 - 2 | June 22, 2026 |
All May 9, 2026 results & picks →
Math-only prediction: no LLM calls used