TrapMetricsTrap bias at Valley: which traps actually win
Trap bias at Valley measured on 4,156 races over 2 years: share of wins by trap against fair share, by distance and by grade, with the noise called noise.
Over the last 2 years at Valley, 4,156 races, trap 6 has been a clear plus at +2.6 points against its fair share and trap 4 a clear minus at -1.9; the other traps sit inside noise. The track is 380 metres round, measured from our own split times.
All distances
| Trap | Runs | Wins | Win rate | Share of wins | Fair share | Bias | Read |
|---|---|---|---|---|---|---|---|
| 1 | 3,661 | 674 | 18.4% | 16.2% | 16.1% | +0.2 | noise |
| 2 | 3,947 | 710 | 18.0% | 17.1% | 17.3% | -0.2 | noise |
| 3 | 3,947 | 694 | 17.6% | 16.7% | 17.3% | -0.6 | noise |
| 4 | 3,908 | 632 | 16.2% | 15.2% | 17.1% | -1.9 | clear |
| 5 | 3,869 | 707 | 18.3% | 17.0% | 17.0% | +0.0 | noise |
| 6 | 3,473 | 739 | 21.3% | 17.8% | 15.2% | +2.6 | clear |
Trap 1 sits inside noise at +0.2 points. Trap 2 sits inside noise at -0.2 points. Trap 3 sits inside noise at -0.6 points. Trap 4 is a clear minus: 15.2% of wins against a fair share of 17.1%, -1.9 points on 3,908 runs. Trap 5 sits inside noise at +0.0 points. Trap 6 is a clear plus at Valley: it wins 17.8% of races against a fair share of 15.2%, +2.6 points on 3,473 runs.
By distance
Only distances with at least 1,500 runs get their own chart; a bias that shows at one trip and not another is usually the run to the first bend at work.
260 metres, 2,402 races
Trap 1 sits inside noise at -1.3 points. Trap 2 sits inside noise at -0.3 points. Trap 3 sits inside noise at -0.3 points. Trap 4 sits inside noise at -1.4 points. Trap 5 sits inside noise at -0.3 points. Trap 6 is a clear plus at Valley: it wins 19.1% of races against a fair share of 15.5%, +3.5 points on 2,066 runs.
460 metres, 1,703 races
Trap 1 sits inside noise at +2.1 points. Trap 2 sits inside noise at -0.4 points. Trap 3 sits inside noise at -1.0 points. Trap 4 is a clear minus: 14.9% of wins against a fair share of 17.3%, -2.4 points on 1,599 runs. Trap 5 sits inside noise at +0.6 points. Trap 6 sits inside noise at +1.1 points.
By grade
Grade letters grouped: A for graded races, D for sprints and dashes where the track uses them, S for stayers, and so on.
| Grade | Races | T1 | T2 | T3 | T4 | T5 | T6 |
|---|---|---|---|---|---|---|---|
| D | 2,280 | -1.1 | -0.1 | -0.3 | -1.5 | -0.4 | +3.3* |
| A | 1,554 | +1.5 | -0.6 | -0.8 | -2.1 | +0.9 | +1.1 |
| O | 296 | +3.7 | -0.4 | -1.5 | -4.8 | -0.4 | +3.3 |
Bias in points against fair share; * marks a clear bias.
The market and the fields
The Betfair favourite won 41.2% of 4,144 priced races here over the window. 70% of races went off with six runners; the rest had a vacant trap, which is why fair share is measured on runs and not assumed to be one sixth.
How to read this
Fair share is each trap's share of the runs, so a vacant trap 6 does not hand trap 5 a bias. A bias is called clear only when it is at least 1.5 points and at least 2.5 standard errors from fair on the runs behind it; anything smaller is a difference inside noise, and the page says so. The window is the last 2 years, refreshed whenever this page is rebuilt. The live version, with the going and our own accuracy at this track, is on the track page.
Questions this piece answers
Which trap wins most at Valley?
Over the last 2 years trap 6 has the largest share of wins, 17.8% of 4,156 races. Against fair share the picture is: Trap 4 is a clear minus: 15.2% of wins against a fair share of 17.1%, -1.9 points on 3,908 runs. Trap 6 is a clear plus at Valley: it wins 17.8% of races against a fair share of 15.2%, +2.6 points on 3,473 runs.
How is fair share worked out?
Each trap's fair share is its share of the runs, not one sixth. A trap that was vacant in many races has fewer runs and so a smaller fair share; comparing its wins with a sixth would invent a bias.
How often does the favourite win at Valley?
The Betfair market favourite won 41.2% of 4,144 races with a settled price over the last 2 years.