Liske started his pro career with the New York Jets of the AFL in 1964. The strong armed QB broke into the CFL in 1965 with Toronto. It was one of those so-so rookie seasons (47.1% completion percentage and more interceptons than TDs), but better was to come. The better times however would not be with Toronto, as Liske moved West to Calgary in 1966. 1966 was an improvement with a completion percentatge up to a more respectable 51.5% and 2177 yards passing. 1967, however, was the big year in Liske's career as he comleted 303 out of 508 passes for 4479 yards and a 59.6% completion percentage. He also threw 40 toudhdown passes to only 25 interceptions. In many ways it was the first big passing season and opened up the modern era of the CFL as a "passing game". Liske was both a West and CFL All-Star in 1967. 1968 was not quite as good, but Liske did have his second straight 4000+ yard season passing and his completion percentage actually rose to 61.9%. Unfortunately for the CFL, Peter LIske went south after 1968, signing with the Denver Broncos of the AFL. LIske spent four years in the AFL and NFL with Denver and Philadephia, before returning to the CFL and Calgary in 1973. Liske had some decent numbers, but never regained his previous highs, and was traded to BC late in 1974. He played one more season with BC in 1975.