VAKYR 的即時入球概率可信嗎？檢驗 341,846 次讀數

Most live football sites show the score and the minute. At VAKYR we wanted to show something more useful during a match: how likely another goal is. Publishing a probability is easy; publishing one that means what it says is the hard part. This is how we check ours.

What the number is

For every live match we cover, from the Premier League to the second division in Kenya, VAKYR shows the probability that at least one more goal arrives before the end of the half or of the match. It is recalculated every few seconds from the live statistics we receive: shots on target, total shots, corners, the score and the minute. You can see it working on VAKYR Live.

The test: does 25% mean 25%?

A probability is calibrated if, across many cases, events it gives 25% happen about 25% of the time. So we log every number the page actually showed, together with what happened next.

Over 341,846 readings, the number promised a goal 24.9% of the time on average, and a goal arrived 24.7% of the time.

Two details matter more than the headline:

• We measure the column people see. Our engine also computes a fallback value. Measured on that fallback, the model looked 4 points off on 38,198 readings, consistently over two periods: a perfect-looking bug that was not real. Measured on the value actually on screen, the error was under 1 point. A rigorous test on the wrong column is the most convincing mistake there is.
• Walk-forward, never in-sample. Every recalibration we tried was trained on older days and tested on newer ones. Three times, a recalibration that looked better in-sample made the live number worse on new matches, so we kept the original.

Does it separate matches?

Calibration alone is not enough: a model that always says 25% would be calibrated and useless. Sorting readings into ten groups from the lowest to the highest number, the real goal rate moves by about 17 points between the bottom and the top group. Not magic, but real information.

We also measured which live statistics actually predict a goal. Shots on target over the whole match and goals already scored add the most separation; the last 15 minutes of pressure add less than people expect, and corners add very little.

What it cannot do

It does not see the future. Some matches with a high number end 0-0 and some quiet matches suddenly score. Live data also arrives with a short delay from the provider, as on every free live score site. The number tells you which matches are more likely to produce a goal, honestly, and nothing more.

Try it

VAKYR is free and runs in the browser, in English, Spanish and Italian. Before kick-off it also publishes probabilities for 739 leagues and cups, with a public record of every prediction checked against the result.