I have both. My Anomaly has a 5" pin-to-PAP, 75 degrees, with the pin just above my ring finger and no x-hole. My Fear Factor has a 4" pin-to-PAP, 25 degrees, with the pin above the ring finger and an x-hole on the VAL in the thumb positive quadrant.
The Anomaly is my benchmark ball - first out of the bag. It is the most controllable ball that I currently own. I can't send it wide because it won't make it back. It appears to lay off at the pins, but it actually hits great. I like this ball for when there is no taper at the end of the pattern because it tames the reaction. I keep the surface at 500 grit, using an Abralon pad. I tried it polished and didn't like the reaction - it didn't do much. This ball has saved my bacon on more than one occasion when my other stuff is too over/under.
The Fear Factor is a ball that I can only use on really heavy oil, so I haven't used it much. It covers a lot more more boards than the Anomaly and it has a much bigger back end. Where the Anomaly backs off at the pins, the Fear Factor just keeps going. I have kept the Fear Factor's cover in box condition.
In my arsenal (see my profile for more details), the Anomaly is a medium ball and the Fear Factor is an oiler.
I hope this helps.
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RW (THB)