Boom Queensland filly heavily backed in the Arrowfield Sprint Posted by: Adam Page+ at 10:39am on 17/4/2021 Queensland filly Isotope has been the key firmer overall with Sportsbet.com.au for the Arrowfield Sprint (1200m) this Saturday at Randwick. The Tony Gollan trained three year old resumed with a strong win in the Darby Munro and should be further suited on the firmer track. $4.40 was first put up on Tuesday and she now sits at Favourite for the race is the class runner of the field, September Run. $2.25 was her price on Tuesday, which was silly short. Got to $3.40 but is now at