I wagered the "over 9 1/2 rounds" on the Mayweather/McGregor fight at 5dimes and thought it was a winning wager but it was graded as a loss. What I found out was that the 1/2 applied to the 10 round not the 9th.

"Those wager was graded correctly, 9.5 rounds means 9 whole rounds and half of the 10th round. The fight ended on the 10th round... 1 minute and 5 seconds into the fight. The wager was lost by 25 seconds.
A total listed on a fight represents the total number of completed rounds. The halfway point of a round is at exactly one minute and thirty seconds into a three minute round. Thus, 4 rounds would be one minute and thirty seconds of the 5th round. The halfway point of a two minute round is at the one minute mark. The halfway point of a five minute round is at the two minutes and thirty seconds mark."

Hopefully that information will help others.

Cheers!