Here is an interesting alternative and me attempting to apply some outside of the box thinking a la Ricon de Paul

Assume that the chance of Horse 1 winning is 10.1%, 2nd place is now effectively the winner of a race home containing the rest of the field, the total probability available now for the remaining runners being 100 - 10.1 = 89.9%

Whilst I appreciate that we are not talking independent events here, this model is one of many races happening simultaneously with decreasing field size, which is effectively what is happening. The total probability remains the same however = 1.00 or 100%

Just my deluded thoughts. Not enough funny water here to make them logical!

LG

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The trick isn't finding profitable angles, it's finding ones you will bet through the ups and downs - UB