In the 8.10 at Chelmsford today there are bang on 16 runners in a handicap. Bookmakers do not like 16 runners in handicaps, perhaps even more so than 8 runners in a handicap. It always seems however that they have little to worry about. Doesn’t one always come out and drop the runners to 15 or less. The punter friendly each way terms of 16 runner handicaps seemed to be inevitably snatched away from them by a non runner or two.

Is something going on here or are we imagining it. Is this the equivalent of a football manager bung, with trainers getting a brown envelope for saving the bookmakers thousands of pounds ?.

Lets look at some figures covering 2009 to 2011 inclusive for handicaps across both Flat and NH.
It shows the number of decs, number of races for that many decs, number of NRs and the NR percent expressed in relation to total decs for that dec size race.
This is for hcps only.
We can see that for 8 dec races there was 1646 such races and they were subject to 1058 NR’s which is 8.03% ie 1058 / (1646 * 8).
This is below the total NR percentage across all races of 8.62%
16 decs by comparison stand at 10.39%
Is there a confounding reason why 16 runner races would get more NR’s as a percentage ?
There does seem to be a spike around the 15,16 and 17 dec’ mark although quite why 15 decs should be spiking is a puzzle

 Decs NumOfRaces NRs NRpercent 1 1 0 0 2 3 0 0 3 22 6 9.090909 4 148 30 5.067568 5 468 143 6.111111 6 863 375 7.242178 7 1199 580 6.910521 8 1646 1058 8.034629 9 1554 1104 7.893608 10 1630 1374 8.429448 11 1550 1416 8.304985 12 1740 1769 8.472222 13 1312 1535 8.999765 14 1369 1756 9.162058 15 529 853 10.74984 16 613 1020 10.39967 17 420 738 10.33613 18 247 397 8.929375 19 61 95 8.196721 20 170 260 7.647059 21 22 53 11.47186 22 32 61 8.664773 23 7 2 1.242236 24 28 25 3.720238 25 3 4 5.333333 26 3 11 14.10256 27 10 18 6.666667 28 10 17 6.071429 29 8 9 3.87931 30 7 6 2.857143 31 2 9 14.51613 32 2 7 10.9375 34 2 3 4.411765 35 2 3 4.285714 36 1 4 11.11111