What is percentage book / overround?

Percentage Book (Overround)
The percentage book indicator or overround  appears at the top of the betting screen and indicates how competitive the odds are in a particular event.  The closer to 100%, the better the value to the backer.

On BETDAQ, most football matches eventually close to between 100 and 101%.  This compares to traditional bookmakers who would normally bet to 112%.

By selecting to Display Overround from My Preferences, you will be able to see the percentage you are proposing to bet to when you are filling in your betting slip