If I was limited to six balls for a tournament, these are the balls I would take:
Storm Phaze 2
This has been one of my favorite balls for years. Usually first out of my bag, this is a great benchmark ball, very versatile, and usable on a wide variety of patterns.
A cleaner, more angular asymmetrical ball. This is a strong ball that I use when I transition away from stronger, solid covers. This ball gives me more length and stores energy for the back part of the lane while retaining the ability to handle a lot of oil.
This is a strong symmetrical ball for heavy volumes. I can use it on many different pattern lengths and I love the controllable shape it gives me. Great option if I need a smooth shape on fresh conditions.
This is my favorite current strong asymmetrical ball. I love asymmetrical cores for long or high volume patterns because they give me a little extra help hooking in heavy oil.
I love the predictability of a low flaring ball. I typically use this ball on lighter volumes or drier conditions. The cover gets it through the fronts easily, and it is great for controlling the back part of the lane.
This ball is great for high friction environments. It is one of my cleanest, most angular balls. It comes into play when I need to get the ball down the lane and cover lots of boards late in blocks.