Jockey Bias: Southwell AW

Depending on your point of view the jockey is either a crucial factor when striking a bet or they are just carried along for the ride. One thing is for certain – when things go wrong they are the first ones blamed.

The betting public will have their favourites, either because of the jockey’s profile or because they booted home a well-backed winner. In terms of mathematical analysis, there is scant information around.

In an attempt to add more science to the process, we have investigated every ride on Southwell’s all-weather track since the start of 2008.

Actual wins v Expected wins: 1/1/08 to 31/12/12

The table depicts number of actual wins above or below expected number of wins, when taking into account bookmaker margin. E.g. If a jockey raced 10 times on a 9/1 chance, you would expect 1 winner and the difference between actual & expected wins = 0

There are several caveats to note:
• Sample size limited to jockeys who have raced 85 times or more.
• Date range goes back five years to increase the sample size.
• Excludes 2-year-old races.
• Table doesn’t take into account race distance because the sample size would be too small. e.g. a jockey might ride 6f better than 2m.
• We assume the SP of a horse is a true reflection of its chances.

Any jockey with a positive ‘minus overround’ rating is winning more races than would be expected when you take into account the bookmaker margin on SPs.

Star performers:
Adrian Nicholls
Frankie McDonald
Paul Pickard
William Carson
Barry McHugh
Win 30%+ more races than they should according to the SPs of their mounts.

Room for improvement:
Ann Stokell
Andrew Elliott
Adam Kirby
P J McDonald
Lose 30%+ more races than they should according to the SPs of their mounts.