On the first of every year, Kreskin appears on national television and makes predictions for the coming year. He is never wrong. Ever. Really.
The magician appears in public and makes several predictions about the coming year, such as "The Superbowl will be won by an American team," or "A magnitude 4.6 earthquake will strike the corner of Wilshire and La Cieniga in Los Angeles at 4:57 p.m. on October 23." Because the predictions were made on television, they are recorded, and at the end of the year can be reviewed. When they are reviewed, it is confirmed that they were correct.
On live television, the magician makes predictions that are either vague ("Something bad will happen to a person of average height") or obvious ("There will be weather next year.") As the year proceeds and newsworthy events occur, the magician sneaks back into the TV studio and rerecords the audio of the taped predictions, making sure that the new predictions match the lip movements of the old ones. When the tape is played at the end of the year, the startling predictions have undetectably replaced the lame ones, and since nobody will remember the original broadcast, the new tape will be taken as evidence of a miracle.