In the North American version of the game, the characters' baseball cards' rookie years each refer to the when their debut games were released in said territory: for instance Mario's rookie year being 1981 due to debuting in the original Donkey Kong arcade game of that year; and Peach, Bowser, and Toad's rookie years being 1985 due to debuting in Super Mario Bros. of that year.
Three characters' rookie years are false: Luigi's rookie year is listed as "1982", but Mario Bros. that he debuted in was released a year later in 1983. Princess Daisy's rookie year is listed as "1990", but Super Mario Land that she debuted in was released in 1989 in Japan and North America but wouldn't be released to PAL territories until the next year in 1990. Funky Kong's rookie year is listed as "1999", but he debuted in Donkey Kong Country in 1994 that Diddy Kong also debuted in. The year 1999 refers to the release of Donkey Kong 64, which the only character to have that rookie year accurate is Tiny Kong whom debuted in that game.