It seems to me that you NEED redundancy or coverage, in the multi-horse wagers.
Why not just play the overlay horses straight??
Lets say we played a Pick-6.
For simplicity every horse was 4-1 on the board, and 3-1 in actual fair odds (25% chance of winning).
You are sitting on a GOLD MINE.
You've got 6 nice overlays in a pick 6??
HUGE EDGE $$$
what are the odds of hitting??
25% 6races = .25^6 = 0.000244141
or 2 hundredths of a percent.
Out of ten thousand plays (good luck finding ten thousand plays like that), you should average 2.4 wins.
You'd be way ahead $$$
, but that is a lot of plays to get your 2.4 wins...
and let's be clear that 2.4 is an average amount of wins for 10,000 plays. There is no guarantee that every 10,000 play sequence will even have 1 winner.
and out of 100,000 plays it would not be improbable to lose as many as 47,151 in a row!
Big numbers.
What it all means, is that when dealing with low% plays, that even if you have a huge edge you are essentially
exposing yourself to
randomness.
Redundancy/Coverage works when you maintain some of the edge, while raising your hit% enough to reduce some of the randomness to workable numbers.