Underbet and overbet Derby horses

The "Calvin Borel effect" has played a role in Saturday's Derby odds. AP Photo/Ed Reinke

The Kentucky Derby is one of the most popular and unique events in all of sports. One of the rare things the Derby offers -- unlike nearly every other race run during the year -- is that wagering is spread out over two days.

The betting pools open up the day before the Derby for advance wagering, and usually around $1 million is put through the windows Friday. At the conclusion of Friday's races the pools close for the night, but it's usually fascinating to see what the betting public does during the first day.

The lion's share of the money will still be bet on Derby Day, but there are always some potential overlays, underlays and odds you just have to scratch your head about.


Twice the Appeal (No. 3 -- 7-1 after Friday's wagering)
The Calvin Borel "factor" is quite apparent with this colt, since his race record isn't all that spectacular. Borel, who has been aboard three of the past four Derby winners, has helped drive down the price on this horse from the 20-1 morning line to the co-second choice.

He has yet to run against this caliber of horse, and if any other jockey was aboard this colt, it is likely he would be at least 30-1. He is likely not a good play at short odds.