I prefer ball shapes that are smoother and less angular. Because the lanes don't transition as drastically for us lefties, it is rare that I need to move deep inside and use a ball with alot of torque. I've found that using strong asymmetric balls that are angular leave more 7 pins than are desired. Having a ball motion that is smooth that can store energy and be played towards the outside will yield better carry.
+1 for this comment.
I have multiple equipment options, majority being symmetrical
I have the most success with balls that are predictable and have controllable motion downlane.
Also, keeping your angles straighter is almost always preferred, especially on tougher patterns.
Right now the 2 pieces that have helped me the most are technically both aysmmterical, but don't really act like it
Hammer Gauntlet Fury - this ball alone has raised my average 6 pins late in the season
Its just money when there is a defined friction spot. It has widened my target area for the house patterns.
Track Ultra Heat - weaker piece allowing me to play straighter, retains energy well, but very predictable.
I also picked up another GB2, symmetrical, super predictable, benchmark piece for me and only $115.00
I'm always looking to play straighter up the boards if possible, you have a far better chance of keeping the ball in play and carrying when you are in the pocket area
Just my personal .02 worth
I used to really turn the ball in my youth, wildly as well, had multiple honor scores.
But when I decided to try the sport patterns, I quickly learned that I didn't really know anything about fundamentals, That was 7-8 years ago.
I'm now constantly trying to get better, reading, practicing, asking for help from others willing to share and teaching others who ask.