Just finished TWO very good books
http://www.amazon.com/Drunkards-Walk.../dp/0375424040
The Drunkards Walk How Randomness Rules Our Lives
and
Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets by Nasim Taleb and these have profound implications on the predictive nature of a wager in that there will ALWAYS BE a bit of unpredictability in any attempt at judging the future and we must confront that truism or be exiled to constant frustration.
Realize how a slight bump at the gate, a rough trip, jockey dropping the stikck etc, can change the outcome by things one has NO ability to predict, or a horse suddenly "woke up" or was jolted (phenomenologically).
In exotics this mean the oft use of the "all" or near "all" at a point in the wager. I often get the SPLITZACTA (first and third with many a long long price in between) and since accepting the randomness these previously frustrating situations have graduated to profits.
Biggest shots are in the baby races where you ride the coat tails of a single good horse to the completely random field of many first timers and the payouts, particularly when that horse runs third, are big time