Billy Muffett was born on September 21, 1930 in Hammond, Indiana. The Muffetts moved to Fort Worth, Texas, where Billy attended Circle Park Elementary School and North Side High School.

He played American Legion baseball and for the high school team, also played basketball and was on the track team. He completed high school in 1948 and was signed by the Shreveport Sports in the Texas League. Shreveport placed him with the 1949 Helena (Arkansas) Seaporters in the Class-C Cotton States League. 

In 1950, he had a good year with a 2.99 ERA in 205 innings of work. In 1951 he followed with a very good year, 22-9 (2.25) for Monroe. He was briefly with Shreveport and his ERA led the league, was a league All-Star and voted league MVP.

The Korean War was on, and the Army needed men. Billy spent from February 1952 to February 1954 in the service, almost all the time at Fort Sill, Oklahoma.

He pitched for Shreveport in 1954, but suffered an arm injury in a spring training game. He began the 1955 season on a Los Angeles Angels contract, placed with Single-A Macon. There he blossomed once more, despite being in Double A, going 10-4 (3.05) and pitched a no-hitter in the Texas League playoffs. In November the St. Louis Cardinals selected him in the Rule 5 draft. He trained with the Cardinals in the spring of 1956, and was the last pitcher cut from the staff. he spent almost the full season pitching for the Texas League’s Houston Buffaloes. 

In the springtime, he trained with the Cardinals again in 1957, but on the eve of the season, he was sent to Houston. Just a few days before he was credited with the victory in the Texas League All-Star Game, he was called up. His major-league debut came on August 3rd.

The Cardinals didn’t wait long to sign him for 1958. His role was as a reliever, although he did get six spot starts in 1958, when he had returned to the Cardinals after a brief three-game stretch in Triple A with the Omaha Cardinals. 

In October he was traded to the San Francisco Giants, part of a five-player trade. He didn’t help the Giants much at all in 1959. He pitched a third of an inning in April, giving up four base hits and two runs in working to five batters and three days later he was sold outright to the Phoenix Giants. In June he was recalled to San Francisco and pitched in four games over the next two weeks.

After being idle for three weeks, he was traded to the Boston Red Sox. The Red Sox assigned him to their Triple-A team, the Minneapolis Millers. He saw postseason action in the Junior World Series, pitching for Minneapolis against the International League’s Havana Sugar Kings. In the Caribbean Series that winter, played in Panama in February 1960, he pitched for the Rapinos of Venezuela. 

The Red Sox brought him to Scottsdale for spring training in 1960 as a non-roster invitee, but he was placed with Minneapolis again. He was brought up to Boston at the end of June, first appearing against the White Sox. In all, he started 14 games and relieved in nine others; he was 6-4 (3.24).

1961 was the only year Billy stayed in the big leagues from the beginning of the year to the end. He mixed starting (11 games, eight of them losses and only one a win) and relieving (27 games), and wound up with a 3-11 mark and 5.67 ERA. He’d had a kink in his arm in spring training, then put on quite a lot of weight while inactive and never really got going.

He turned up for spring training some 18 pounds lighter than in September 1961. In April 1962, he started and worked four innings against the White Sox, yielding four runs on eight hits and two walks. It was his final game in the majors. In May, he was sold outright to the Seattle Rainiers. His major-league totals were 16-23 with a 4.33 ERA.

In June he was traded to the Atlanta Crackers (International League) and pitched three more years, all in the minor leagues. In 1963 and 1964, he was with the Richmond Virginians. In 1965 he he pitched for the Double-A Texas League Tulsa Oilers, for whom he also served as pitching coach.

In 1966 he worked as the organizational pitching coach for the Cardinals, making the rounds of the farm system. In October, he was signed to become pitching coach for the St. Louis Cardinals themselves, and won a World Championship ring as the Cards beat the 1967 Impossible Dream Red Sox.

It was the first year of 18 as a big-league pitching coach. He worked for the Cardinals through 1970, then with the Angels from late in the 1974 season through midseason 1977, and finally with the Detroit Tigers from 1985 through 1994.  He spent 1978 out of baseball, but was hired by the Tigers as their minor-league pitching coach in 1979. After his 10 years as Detroit’s major-league pitching coach, he retired following the 1994 season.

In retirement, he worked with semipro and youth baseball groups in his community and with annual baseball clinics, something he enjoyed doing during the winters and continued to do for many years.

Billy Muffett died on June 15, 2008 at his home in Monroe, Louisiana. He was 77 years old.