Labs / Draw Bias
Measure whether the stall matters at any course and distance, and find out that at most tracks it does not. The interval is the point of the tool.
A sample of what it prints
Takes a course and a distance, splits every field into low, middle and high thirds by stall, and scores each third against its own market rather than against winning. A stall that wins often because good horses are drawn there is not a bias; a stall that beats its price is.
Thirds rather than individual stalls, deliberately. Stall numbers across varying field sizes produce rows with a handful of runners each and an apparently dramatic pattern that is entirely noise.
python draw_bias.py --course "Chester" --distance 5f --min-runners 8
One command, start to finish. It fetches what it needs, caches it under /data so a second run costs nothing, and prints the table.
These rows are illustrative. They show the shape of the output and will be replaced by a real run before this is published. Nothing here should be quoted as a finding yet.
Run across every British course at every distance with at least four hundred qualifying races.
| Course | Distance | Third | A/E | Interval | Runners |
|---|---|---|---|---|---|
| Chester | 5f | Low | 1.18 | 1.06–1.31 | 4,180 |
| Chester | 5f | High | 0.84 | 0.74–0.95 | 4,102 |
| Beverley | 5f | High | 1.14 | 1.02–1.27 | 3,340 |
| Sandown | 5f | Low | 1.03 | 0.92–1.15 | 2,908 |
| Ascot | 1m | Low | 0.99 | 0.90–1.09 | 5,214 |
This one is still being written. When the repository is up, this page gains the link and the card on Labs flips to published. We would rather say that than point you at nothing.