Is an odds on favourite less likely to win the more horses in the race?

[Zico10]

I was wondering if there's any correlation between the likelihood of a favourite or odds on horse winning? So does an evs favourite win more often in say a 5 horse race as opposed to an evs favourite win a 7 or 8 horse race? 

[richard-westwood]

I would think the more runners the more likelihood that the x factor happens ....a horse falls in front of you .....you meet trouble in running or something improves on day and takes you on ....there must definately be a link between that and number of runners 

[Valiant Thor]

3 hours ago, Zico10 said:

I was wondering if there's any correlation between the likelihood of a favourite or odds on horse winning? So does an evs favourite win more often in say a 5 horse race as opposed to an evs favourite win a 7 or 8 horse race? 

0-5 runners @ evens or less ROI 95.33% ROI approx loss of 5p in the pound (from 16381 races)

7-8 runners @ evens or less ROI 92.80% ROI approx loss of 7p in the pound (from 42651 races)

9-10 runners @ evens or less ROI 90.28% ROI approx loss of 10p in the pound (from 3366 races)

11-12 runners @ evens or less ROI 89.55% ROI approx loss of 11p in the pound (from 1734 races)

13-14 runners @ evens or less ROI 71.66% ROI approx loss of 29p in the pound (from 901 races)

15-16 runners @ evens or less ROI 74.51% ROI approx loss of 26p in the pound (from 595 races)

Edited November 14, 2018 by Valiant Thor

[Zico10]

Thanks. I assumed that would be the case but it's interesting seeing the figures.