I can't find any specific information on the pattern other than it is 39 feet and it tends to be higher scoring. I would bet the ratio is in the 2.5:1 area or maybe even more.
At 39' you've got a lot of options for angles to play, but its always best to start as far right as you can. That will give you more hold and more swings as you move in. If you start too far left, you will create over/under.
Balls to use very much depend on how you throw the ball. Mika shot 299 and 269 the last two games of the show using a Mission Domination...not too different from your Mission X. That's probably a good starting point, but switch to a dull symmetric ball if you find the Mission too snappy.
Transition in sport leagues is impossible to predict since everyone plays every-man-for-himself. If you could get everyone to start outside of 10, and slowly bump in, you make the pattern easier. If everyone is spraying-and-praying...you just never know what will happen.
Nowadays, I open bowl practice and go to Nationals every year.
USBC Open personal bests: 226/602/1690
USBC Open career average: 174.66 (45 Games)
See you in Reno 2020!