Arlington Park completed its investigation of a suspicious odds drop on the winner of the second race June 28, Rainy Day Rules, announcing Friday there was no proof of any past-post wagering.Odds on the winner dropped from 9-1 at post time to 5.90-1 while the race was in progress."It has been concluded that no wagering took place after the horses left the gate and the tote machines locked," said Arlington Park President Cliff Goodrich. "In the review, conducted in conjunction with the Illinois Racing Board's pari-mutuel auditor, we obtained wagering data from our totalisator provider, AmTote, as well as from the other two tote companies, United Tote and Autotote, who provide service to many of the simulcast locations that take the Arlington Park races. This data proves that no wagers were placed after the start of the race." The vast majority of racetracks in North America, including Arlington, accept wagering until the bell rings and the horses leave the starting gate. While it takes approximately 20 seconds to accumulate and verify all pools are received from off-track locations, no bets can be taken after the host track's computer has been locked. Changes in the odds once the race starts can occur when those late pools are included. Rainy Day Rules paid $13.80, $8.00 and $6.40.