A fitness fanatic, Carlton trained by practicing kung fu, doing isometric exercises, and developing strength in his hands by working them in buckets of rice. It worked for him: The 6-foot-4, 210-pound left-hander became the first pitcher to win four Cy Young Awards.
After pitching briefly for the NL's St. Louis Cardinals in 1965 and 1966, Carlton became a regular starter in 1967. It was the first of 17 seasons in which he made more than 30 starts. In 1968, Carlton added a nasty slider to an excellent fastball and fine control.
His first 20-victory season came in 1971, when he had a 20-9 record. His reward was a trade to the Philadelphia Phillies. Known simply as "Lefty" by his teammates, Carlton won his first Cy Young Award in Philadelphia in 1972, compiling a 27-10 record for a last-place team that won only 59 games. He led the NL in victories and in complete games with 30, innings pitched with 346, strikeouts with 310, and ERA with 1.97.
Carlton's performance won him a $167,000 salary, the highest ever for a pitcher at the time. After three sub-par seasons, he led the NL with a .741 winning percentage on a 20-7 record in 1976, then claimed his second Cy Young Award in 1977, when he led in victories with a 23-10 record.
After going 16-13 and 18-11, Carlton led the league in victories with a 24-9 record, in innings pitched with 304, and in strikeouts with 286 in 1980, when he had a 2.34 ERA and won another Cy Young Award. He claimed his fourth in 1982. That season, Carlton was the league leader in victories with a 23-11 record, in complete games with 19, in shutouts with 6, in innings pitched with 295, and in strikeouts with 286.
Despite a 15-16 record in 1983, Carlton again led in innings pitched with 283 and in strikeouts with 275. He began to slide in 1984, when he was 13-7 with a 3.58 ERA. In 1985, Carlton went on the disabled list for the first time, starting only 16 games and completing none.
Carlton pitched with little success for the Phillies and the San Francisco Giants in 1986, the Cleveland Indians and Minnesota Twins in 1987. He retired after appearing in just 4 games for Minnesota in 1988.
In 24 seasons, Carlton had a 329-244 record, with 55 shutouts and a 3.22 ERA. He struck out 4,136 hitters while walking only 1,833 in 5,217 1/3 innings.