One of the more interesting prop bets as the 2013 Breeders' Cup World Championships unfolds is how many of the seven defending winners will repeat? If I were to accept wagers on the outcome I'd set the over-under line at 1.5 with 3-to-5 on the under and 7-to-5 on the over.

Individual odds would look like this (about 6.5% takeout):

# wins Odds:

0

  3-to-1

1   3-to-2
2   5-to-2
3   8-to-1
4  40-to-1
5+ 400-to-1

I arrived at these odds by assessing the following chances to each of the returning seven winners:

Horse: Race: Odds-1 % chance
Fort Larned Classic 6.00 14.29%
Groupie Doll F&M Sprint 4.00 20.00%
Little Mike Turf 8.00 11.11%
Mizdirection Turf Sprint 4.00 20.00%
Royal Delta Distaff 2.50 28.57%
Trinniberg Sprint 20.00 4.76%
Wise Dan Mile 2.00 33.33%

Given those odds the chance that they ALL win is about 347,000-to-1, which is less likely than randomly picking the Super High 5 in a 14-horse field (240,239-to-1). The most likely outcome is 1 winner followed by 2 then 0.

The art is discerning the odds-to-1 of each of the returning winners. After that it's all science to come up with the odds of a certain number of them winning. Do any of these prices look good to you?