Just had to reply to this!!!
Coventry has always been a challenging centre made more so by the dodgy heating system which in the past has made the lanes either dry out v.fast or become "Spotty"
I bowl at the airport and unless the lanes have oil from the foul line to the pin decks any half decent bowler can ave over 200.Trouble with a lot of uk bowlers <especially the men> is that they can score large on a THS or at specific centres and when they bowl at a "Tough" centre or on a "Tough" patern they struggle.
As for ball choice from what I remeber of Coventry a superpower will be fine if a> The backends are "Snappy" or b> They Dry out as quickly as they usually do.I bowl with two superpowers myself and they tend to do well on med/dry/snappy lanes.As for the ultimate I am hardly a Rev-master and I bowl with a dull version which has also been plugged twice and tracks over the plugging and still carrys like no other ball I have ever had so don't understand why you are having so much trouble with it.
Anyway to anyone bowling at the nationals good luck and hopefully I'll be competing at the next two events <Nuneaton and Croydon> this year.