Tennis Moneylines

Both tours have used Serve/return v1 since September 20, 2026. It adds opponent-adjusted serve and return rates from each player’s past 365 days to the overall and surface Elo ratings of Elo v1, the previous model, which still decides who has enough history for a forecast. It was promoted as an experiment: development testing did not show a reliable accuracy gain over Elo v1. Neither model has established a betting advantage, and on settled matches through September 22, 2026, DraftKings’ no-vig price was the more accurate forecast. Use forecast results to inspect the size and quality of the saved live sample.

Probabilities estimate the winner of a completed match. Fair lines exclude bookmaker margin. DK no-vig is DraftKings’ implied probability with its margin removed; Model vs DK is the model’s probability minus that figure, in percentage points. Break-even is the win rate a bet needs to profit at DraftKings’ offered price (1 ÷ decimal odds), so it includes the margin and is higher than DK no-vig. The board shows no expected value: so far, the model’s disagreements with DraftKings have not predicted results better than DraftKings’ own price. Because the two win probabilities add to 100%, fair American lines are equal and opposite: 71.4% / 28.6% is approximately −250 / +250. Missing prices mean we have no verified pair from our odds feed; a match may still be listed at DraftKings. Retirements and walkovers are excluded from model evaluation.

Matches stay on the board until midnight Eastern on their date. When a scheduled start passes with no play seen, as when a match is delayed, the card stays up with the model’s last prematch forecast and the time it was made; the model does not update after the scheduled start. DraftKings prices are hidden from either listed start, because a price after the start may be a live price rather than a prematch one. Matches in progress and finished matches follow with their prematch pick and result. A match still unfinished at midnight, such as a late start delayed past it, stays listed until it finishes or the next date ends, on its own date and on the next date’s board. A match whose start moves past midnight is listed on the next date.