Tennis Match winner: devig calculator
- Market
- 2-way
- Typical overround
- 3%–7%
- Sample overround
- 3.70%
- Worst-case probabilities are per-outcome minimums and do not add up to 100%.
| Outcome | Multiplicative | Additive | Powerk = 1.059 | Shinz = 0.037 | Worst case |
|---|---|---|---|---|---|
| Outcome 1 | 64.29%1.556 | 64.81%1.543 | 65.08%1.537 | 64.81%1.543 | 64.29%1.556 |
| Outcome 2 | 35.71%2.800 | 35.19%2.842 | 34.92%2.864 | 35.19%2.842 | 34.92%2.864 |
- Overround
- 3.70%
- Margin
- 3.57%
- Outcomes
- 2
Overround 3.70%
Tennis match winner is a two-way market, but retirement rules differ: some books void if a player retires before the first set is complete, others pay out immediately. Matching rules across books matters for arbitrage.
Overround in this market
Tennis Match winner has 2 outcomes (
Player A, Player B). Bookmakers usually price it with an overround between 3% and 7%. Sharper books sit at the low end; recreational books and multi-way fields at the high end.
Worked example
Sample prices of 1.50 / 2.70 carry an overround of 3.70% (margin 3.57%). Multiplicative devigging gives fair probabilities of 64.3% / 35.7% and fair odds of 1.56 / 2.80. The calculator above starts from these prices and shows every method side by side.
| Outcome | Odds | Implied | Fair probability | Fair odds |
|---|---|---|---|---|
| Player A | 1.50 | 66.7% | 64.3% | 1.56 |
| Player B | 2.70 | 37.0% | 35.7% | 2.80 |
Method choice
In this 2-way market, with prices this close, the methods agree closely. Differences appear when one side is a heavy favourite; then the power and Shin columns are the ones to trust for the outsider's fair price.
Frequently asked questions
What is a normal overround for Tennis Match winner?
Between 3% and 7% at most bookmakers. Lower means a sharper book; multi-way fields run higher.
Which devig method should I use for Tennis Match winner?
With 2 outcomes priced close together the methods agree. When one outcome is a heavy favourite or the field is large, power or Shin better model where the margin sits; worst case gives the most conservative probability.
What are the fair odds for the sample prices?
The sample prices 1.50 / 2.70 carry an overround of 3.70%. Multiplicative devigging gives fair probabilities of 64.3% / 35.7% and fair odds of 1.56 / 2.80.
Can I use the fair probability to size a bet?
Yes: enter it with an offered price in the EV & Kelly calculator, or use the devig calculator's price-check panel, which reports edge and Kelly stake for each method.