I have seen 2 conflcting reviews of this ball in BJI and BTM. From them I'd suspect it may not be the ball for your father.

 

I'd recommend a polished solid rather than a pearl, which are, in many cases, either too strong for slower speeds (of which I am one) or are drilled too "normally" for an average ball speed bowler, in which case, they have too much backend to control.

 

I'd suggest consider balls, like the Roto-Grip Riot, and have it polished medium.  For true medium ball, such a ball will work well for an ol older bowler with decent revs but slower ball speed. There are ways to modify drillings for control or milder pearls to make sure they are controllable. The good driller will always, ALWAYS want to watch this bowler to see just what his ratio of speed to revs is, before even trying to drill him a ball. The Visionary Blue/Green Centaur and the Track 300T are more examples, but polished they will handle a little bit less oil than the polished Riot. (None of the 3 balls comes polished as stock.)

 

Just in case, there are a few balls just below these in oil handling ability that are potential alternatives for less oil: the new urethanes: The Brunswick Avalanche Urethane (a Pearl and comes polished as stock)) and the Hammer Blue Hammer (might need some polish) are very valid choices.

 

Good luck.