24.85mph by Australia bowler Alan Patterson at Hillwood Strike and Spare
I don't know the fastest ball speed in the world, but I can assure you it's not 24.85. I bowl at Sunset Lanes in Richmond, VA, and a bowler on our league throws 26 mph every frame, for three games. The fastest I have seen him roll one is 28 mph. For the record, the ball is 16 lbs and his average is in the 130s, because with that much speed it's hard to also be accurate.
Osku Palermaa, a pro two-handed bowler, has a wicked fast one-handed spare ball. Usually when downing particular spares, like the 10, 6-10, 6, 3-6-10, and most splits, he throws it one-handed. His one-handed shot on average is about 27-28 MPH, not too far away from his 22MPH average strike ball. His fastest on television is, if I'm correct, about 32 MPH at the 2004 US Open, but on his website (oskupalermaa.fi) he claims that his fastest recorded is about 35 MPH. He has one of the strongest, if not the strongest, spare ball in the world, so I'm sure not many will be able to surpass that. Other pros who use fast spare balls include Robert Smith (capable of throwing it as fast as Osku), Eugene McCune (he throws it about 25 MPH as an all-round average, but capable of surpassing 30), and Sean Rash (capable of 30 MPH).
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