He broke into the majors with St. Louis in 1955, posting a record, and gradually worked his way into the starting rotation by 1958. He was named to the NL All-Star team in 1957, 1958, and 1960 while with the Cardinals, and allowed only two hits and no runs in 3-⅔ innings in the three appearances; the 1957 game was played at Sportsman's Park in St. Louis. In 1960 he led the NL with 282 innings and 38 games started, also winning 18 games, but he missed the first four weeks of the 1961 season after having his jaw broken in a late spring training game by a flying piece of Duke Snider's After the 1962 season, Jackson was traded to the Cubs along with Lindy McDaniel in a six-player deal; the Cardinals received three players including Jackson was again an All-Star in 1963, and earned the win despite it being his least effective appearance in the Midsummer Classic; after entering with a lead in the third inning, he allowed the tying runs, but the NL again took a lead in the top of the fifth as he departed. He enjoyed his best season the following year; despite the Cubs' record, Jackson was with 148 strikeouts and a 3.14 earned run average. He also set a major league record for pitchers with 109 total chances without an error, breaking the mark of 108 shared by Three Finger Brown and Eppa Rixey ; Randy Jones broke his record with 112 for the San Diego Padres in. With only one Cy Young Award for both leagues at that time, Dean Chance of the American League's Los Angeles Angels won the award with 17 of the 20 votes; Jackson received two votes, while Sandy Koufax of the Dodgers received one. Jackson lost 21 games in 1965, the first since Murry Dickson in 1951–52 to have twenty wins and twenty losses in consecutive seasons. One of those losses was in ten innings to Jim Maloney of the Cincinnati Reds, who threw a no-hitter with In early he was traded to the Phillies in the deal which brought Ferguson Jenkins to Chicago, and he ended the season as one of six pitchers tied for the league shutout lead with five. In 1967, he won his 171st game to pass Bill Doak, who had previously been the winningest NL right-hander of the 20th century to never play for a pennant winner. On June 20 of that year, he pitched a one-hitter against the New York Mets. After a 13–17 season with a 2.77 ERA in 1968, Jackson was selected by the Montreal Expos in the October 1968 expansion draft, but chose to retire rather than join the team; Bobby Wine was sent from the Phillies to the Expos the following April as compensation. In a 14-season career, Jackson posted a record with 1,709 strikeouts, 37 shutouts, and a 3.40 ERA in 558 games and 3,262⅔ innings. He tied a record held by Claude Passeau by four times having the most total chances among pitchers with a perfect 1.000 fielding percentage.
