For every WTA match, our model produces a single number: each player's win probability. That is the BeatzeBook Index. Here is how it is built, and how we measure whether it is right.
The BeatzeBook Index is a probability, from 0 to 100%. When it gives a player 62%, it estimates she would win about 62 times out of 100 if the match were played many times over. No intuition, no hand-made tips: the same calculation applies to every match, the same way.
Once the Index is computed, we compare it to the best odds from 3 licensed bookmakers. When our probability is clearly higher than the one implied by the odds, that is a signal. The rest of the time there is nothing to do, and that is exactly as it should be.
Recent form, surface, head-to-head history, rest between matches, tournament strength, level of play on serve and on return. Every factor is measured player by player, surface by surface.
The model learns from past results since 2012. It combines several separately trained versions and averages them: one wild estimate carries less weight, and the final number is steadier.
We never judge the model on the matches used to train it. It is always tested on a more recent period it has not seen. That is the only way to know whether it truly works, and not just on paper.
A model that only names the favourite is worthless: bookmakers already do that. What matters is how accurate the number is. We hold ourselves to three measures, and we read them over time, not over a single match.
The goal: players rated 60% should genuinely win close to 6 times out of 10. A well-judged number beats one that often names the right winner but gets the margin wrong. This is our number-one metric.
We compare the signal at the moment it is issued to the final odds, just before the match. If our signals land on the right side of that move on average, it is the most reliable sign they capture real information, not noise.
We track returns with a fixed, identical stake on every signal, never a variable stake that flatters the numbers. It is the simplest measure to verify, and the hardest to game.
A model has good runs and lean ones. That is normal, and anyone claiming otherwise is not really measuring. We are publishing the method today; the verifiable, numbers-based performance record will ship with the next version of the model.
Our job ends at producing the most accurate number we can. What you do with it is up to you.
BeatzeBook is a statistical analysis tool. We do not place bets and do not guarantee any results. Past performance does not predict future results.
The 3 integrated bookmakers are all licensed operators. We encourage responsible gambling.
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