I find it useful , as i said earlier it gets you practising those other high value trebles ! He also used to play 301 only doubles count allowing 0nly 1 dart to take the odd number off! Sharpens up the doubles as you couldnt go for the same double all the time if you for instance hit tops with your first darts you couldnt go back there for 9 darts , Sounds complicated but its not really , honest ! Alongside flight school i will now be incorporating these into my practice routines . Well to be honest my practice routine will be flight school and the above routines , I plan to devote much more time to practice , Im looking at about 4hrs a day starting tomorrow as i gotta get in better shape for the summer league !!