Storm has created the Pitch Blue, a pearl urethane ball, for their Thunder Line. This ball was designed to be cleaner through the heads and more reactive at the backend on lighter and shorter oil conditions. The Capacitor core gives this ball a straighter but strong delivery.
I use this ball for my spares mostly but when I'm bowling on a short pattern there isn't another ball i would want to use. Even on a house shot i was able to move way right and throw right down the 5 board and this ball would recover and roll smoothly into the pocket demolishing the pins. This ball rolls a little more than a normal urethane ball. Some urethane balls will sometimes die at the end of the pattern and slap the pins creating bad carry where this ball seems to continue its drive going through the pins. Overall great urethane ball.