Market resolves "YES" if the final margin between the horses that finish 1st and 2nd is less than or equal to a 1/2 length.

If it is not abundantly clear at race finish whether the margin is less than or equal to a 1/2 length, I will defer to online sources for the reported margin. If there is still subjectivity (like disagreements between sources on the margin), I will make the final decision. I will not trade on this market.