Pat Cummings tells the story of pool manipulation and Will Rogers Downs"

"In April 2021, at least three instances of tote pool manipulation occurred in quinella pools at Will Rogers Downs in Oklahoma.

Extremely large wagers, relative to the size of the overall pool, were placed on combinations likely to lose, inflating the actual tote returns on more favored horses.

The goal of such manipulation is to dramatically change the odds on the pari-mutuel outcomes and win far more by betting through a non-parimutuel operator (like a GMO) which pays at track prices and at generous limits. While the manipulated bets on the legal, pari-mutuel pools are expected to be losing ones and inflate the returns for other successful customers, the manipulator aims to make a far larger score through their other plays. There were instances of such manipulation through the mid-1990s at Nevada racebooks before most books stopped booking racing bets and adopted pari-mutuel wagering on racing.

The quinella pool at Will Rogers typically handled between a few hundred dollars to less than $2,000 per race. In the most egregious example of manipulation, which occurred in Race 2 on April 27, the quinella pool totaled $7,469 for this Oklahoma-bred claiming event.

The winning quinella (first two horses in any order) featured the two favorites in a five-horse field and returned an astounding $51.30 for every $1 bet. The exacta with the same horses returned $6.20 while the trifecta with the third choice in betting running third paid $9.60.

What seemed like a gift for favorite backers could have been a nightmare for those who legitimately backed the two longest-priced runners in the small field if that result had materialized. The quinella probable payouts featuring those two horses, who closed at 6-1 and 9-1 in the win pool, would have returned $1.05 for every $1 bet."