Depends on the surface and how much pressure they dial up on the pump when they oil. I've played it mostly right up the center, little swing over third arrow with a nice firm speed, but I've seen people play second arrow, first arrow, fourth arrow and even I who am not a big handed bowler, have been deeper than 4th on beat up wood lanes with guardian heads and light oil. To guess what it will be isn't practical. All you need to know is that on the flat pattern, if the lanes are in good condition, it plays the same everywhere. You get "X" boards of hook no matter where you throw it and it's up to you to find an angle that gives you the best carry. If the lanes are worn, then the track will change the characteristics of the flat shot, giving you an area that will hook a little more than others on the lane, some extra recovery, that you may be able to use to your advantage, maybe.
I get in trouble when I slow down and try to force the ball to do things that the lane doesn't want to give you. I also get in trouble when I go to a ball that is more dynamic, as in drilled for long strong or one with a really rough agressive cover.
Take something along that isn't too strong as you may find it is the easiest to control. On the Open pattern, don't worry about strikes. They are nice when they come, but spares are gold! If you stay out of trouble and keep clean you will be tough to beat. If you try to make up for opens with strings of strikes it will be a really long and painful experience. Good luck! I think this is the most fun pattern out there!