Dave Eiland, who played a relief pitcher in the bullpen and celebration scene, was also Kevin Costner's pitching double in some long shots.
Many of the Yankees players were played by Yankee minor leaguers.
One of the baseball players is Scott Pose, the first player to bat for the Florida Marlins franchise (in 1993).
All four umpires were played by real Major League umpires.
The baseball gloves used by the actors were broken in by the NYU baseball team.
Facing Ken Strout in the bottom of the 9th inning, Chapel says to himself "Think Billy, don't just throw." In the film Bull Durham (1988), Costner's character Crash Davis gave the opposite advice to pitching protégé Nuke LaLoosh when he said, "Don't think. Just throw."
The shots of Billy Chapel's parents at the beginning of the movie are Kevin Costner's actual parents.
A lot of the Yankee hitters use actual Yankee stats from the 1998 season. An example is Matt Crane, the pinch hitter to lead off the ninth. He was hitting .373 with 10 HRs and 27 RBIs. These were Shane Spencer's stats in 1998. Davis Birch used Paul O'Neil's stats.
Half of spectators in stands were "virtual" cardboard people.
The book next to Billy Chapel on the airplane after he finds Heather is "The Killer Angels". This book was also written by Michael Shaara, who wrote "For Love of the Game".
On the DVD, under the "on the mound" section, you can answer a series of questions about the perfect game. If you answer all of these correctly, you will get an Easter Egg: the short black and white film "Play Ball with Babe Ruth" will play.
The scene in which the ball bounces off of Mickey Hart's head is based on the famous incident in which the same thing happened to Texas Rangers outfielder Jose Canseco. Afterward, when Billy and Mickey are talking in the clubhouse, Mickey jokes "It'll probably end up on ESPN." In fact, Canseco's incident became blooper reel fodder for ESPN for the remainder of that year.
The manager of the New York Yankees is played by Augie Garrido, who befriended Kevin Costner while he was the head coach at Cal State Fullerton. Garrido is currently the head coach at The University of Texas and the two remain good friends.
Throughout the film, everyone is talking about what a great pitcher Billy is. One person even says to Billy "You've got a room reserved for you in Cooperstown". There is a visual representation of Billy's past triumphs in the film. During the montage scene of Jane constantly asking Billy questions, in the scene when she asks him how he likes his chicken, the camera pans over to Billy and on the wall to the right, there are three plaques mounted on the wall. Those plaques are Cy Young Awards. The Cy Young Award (Named after the all-time leader in wins with over 500 victories) is given to the pitcher in each league who is the best in the league for that year. Essentially, it means that Billy was the best pitcher in the American League (the league the Tigers are in) on at least three different occasions. The winner of the award is usually the league leader in wins and other major categories like lowest ERA (Earned Run Average) and most strike outs.
The cast lists the Tigers second baseman as Marcus Random, played by Earl Johnson, but in the eighth inning when he fields a ground ball his jersey says "Ransom", not Random. It also sounds like Vin Scully calls him "Ransom" in the play by play.
According to the Fox Sports graphic displayed at the beginning of the game, Billy Chapel's stats for the year (coming into the game) are as follows: 8 Wins, 11 Losses, 30 Games Played, 30 Games Started, 2 Complete Games, 1 Shutout (Meaning in one other game he pitched a full 9 Innings without allowing an opposing run), 211 Innings Pitched, 98 Walks Allowed, and 111 Strike Outs.
After pitching his perfect game at Yankee Stadium, Kevin Costner's character carries John C. Reilly to his hotel room, where Reilly says to him, "you're the cream in my coffee." In Costner's movie JFK (1991) a woman on the street comes up to him asking if he remembers singing with her at a party to which he responds, "oh right, we sang 'you're the cream in my coffee'" as he walks away.