Bill Murray really bowled three strikes in a row in the scene where his character, Ernie McCracken does the same. The crowd's reaction is genuine and is actually for Murray. Woody Harrelson, on the other hand, was a terrible bowler and according to the Farrelly brothers maybe got one or two strikes throughout the filming.
In the big bowling tournament at the end, an unseen person in the stands yells "Attaboy, Luther!". Everytime Don Knotts character speaks in public in The Ghost and Mr. Chicken, an unseen person also yells "Attaboy, Luther!".
In the scene in the bowling alley restaurant just before Ishmael is about to get beaten up, the three are eating burgers and fries. However, Roy is eating a salad because actor Woody Harrelson is a vegan.
Among others, Pro Bowling Hall of Famers Parker Bohn III and Mark Roth appear briefly during the final tournament scene. In one scene Roy shakes Mark Roths hand after defeating him in a head to head match.
As is the case with most of his films, Bill Murray ad-libbed virtually every line he spoke. He would read over the script, get the general idea, and then discard it. The Farrelly brothers, on the DVD commentary, said that they're very glad he did, because it was funnier.
PGA Tour players Brad Faxon and Billy Andrade both appear in two scenes, when Roy enters the bowling alley in the opening sequence, and when he leaves for the first tournament. Both players have numerous wins on tour.
Major League Baseball pitcher 'Roger Clemens (I)' has a small cameo in the film. In the restaurant scene where Roy punches out Ishmael, Roger Clemens plays the part of Skid Mark. Clemens currently ranks 8th on the All Time wins list for major league baseball pitchers.
In the Cheers episode Cheers: From Beer to Eternity Woody Boyd, played by Woody Harrelson, reveals that he is an ex-bowling ace who retired due to crippling a man in a bowling accident. In this film his character is forced into retirement due to a bowling injury at the hands of Ernie McCracken.
lead singer and harmonica player for Blues Traveler, has a bit part as the announcer for the Reno bowling championship. Blues Traveler, in Amish garb, appears at the end of the movie playing one of their songs.