[3] After leaving the University of Kansas at the age of 20, Allison was signed by the Senators as an amateur free agent before the start of the 1955 season.

On September 16, 1958, Allison made his major league debut, batting lead-off, and got a single in four at-bats in a 5–1 loss to the Cleveland Indians.

However, he came back strong in 1961, hitting 29 home runs – including three grand slams – with 105 RBI, although his batting average dropped for the second year in a row, to .245.

[7] Allison hit the first home run in Twins history off future hall of fame Yankees pitcher Whitey Ford.

Other Twins leading the league in WAR include Zoilo Versalles, Rod Carew, and Joe Mauer, all of whom were named MVP in the seasons they did so.

Only Allison did not win the MVP in the same season (finishing a distant 15th behind winner Elston Howard and behind teammates Camilo Pascual, Earl Battey, and Killebrew on the 1963 ballot).

[3] In 1966, he was again hit by a pitch that broke his wrist, and played in only 70 games,[1][3] but returned at the end of the season to knock a pinch-hit three-run homer against the New York Yankees on September 18, 1966.

[15][16] During the Twins' 1965 World Series season, Allison had a down year, after suffering a fractured wrist on July 6th,[3] hitting only .233 in 135 games.

His bases-loaded double against Koufax and a great backhand diving catch of a Jim Lefebvre fly ball were the main contributors to the Twins victory.

Thirteen years after his retirement, Allison began noticing problems with his coordination during a 1987 old-timers game at the Hubert H. Humphrey Metrodome.

Following two years of doctor visits to learn what was wrong, the diagnosis was finally made — Allison was suffering from a progressive sporadic ataxia known as Olivo-Ponto cerebellar atrophy.

He continued to battle this rare degenerative neurological disease for eight years, eventually losing his ability to walk, talk, write, and feed himself.