By contrast, Conley played 18 professional seasons in 12 years. In six consecutive years during which his baseball and basketball careers overlapped, he played 12 professional seasons without taking a break.
Conley played two sports simultaneously longer than dual-sports stars like Dave DeBusschere (basketball and baseball) and Bo Jackson (football and baseball) — indeed, longer than any other two-sport athlete except Deion Sanders, who played both baseball and football for nine years.
Conley’s death was confirmed by his daughter Kelly Conley, who said he had heart failure.
A multiple-sport talent in high school, Conley was more dominant on the diamond than on the court. He started in the Braves’ farm system in 1951, when the team was in Boston. (He pitched in four games for the Braves in 1952.) Throughout his career he relied on a blistering fastball and a deceptive curveball in compiling a record of 91-96 with a 3.82 earned run average.
His wingspan was so great that his fastball appeared “to come out of third base,” Al Hirshberg wrote in a 1955 profile in The Saturday Evening Post.
“I could sling the ball good,” Conley said in an interview for this obituary in 2012. “I pitched nearly my whole career with just two pitches, and if you do that you usually don’t last too long.”
Conley won nine games in his championship season with the Braves, pitching alongside Warren Spahn and Lew Burdette on a team that also included the sluggers Hank Aaron, Eddie Mathews and Wes Covington. But he did not start in the World Series against the Yankees, making only one forgettable relief appearance.
He later pitched for the Philadelphia Phillies and eventually returned to Boston to pitch for the Red Sox. His baseball coaches pushed him not to play basketball, usually to no avail.
Major league baseball in the 1950s was far less lucrative than it is today, and Conley, like most players, needed an off-season job. While playing with the Braves’ Class AAA team, he pitched a game against a Brooklyn Dodgers farm team on which Bill Sharman, better known as a sharpshooting guard for the Celtics, played third base.
Sharman had been impressed by Conley’s basketball talent after seeing him play for Washington State College (now University) against John Wooden’s U.C.L.A. team in the Pacific Coast Conference finals when Conley was a sophomore. After the game Sharman offered to approach the Celtics’ coach, Red Auerbach, to see if Conley could try out for the team.
“He called Red Auerbach and said, ‘I saw this skinny guy from Washington — you should give him a call,’ ” Conley said. “I had no idea who Red Auerbach or the Celtics were.”
Conley made the team as a reserve center and earned $4,500 for the 1952-53 season, appearing in 39 games. His baseball manager was displeased, and the next season the Braves paid him $5,000 not to play basketball. He stayed off the court until 1958, when the Braves cut his salary after he had lost six consecutive games.
Conley won three Celtics championships playing alongside, among others, Bob Cousy, Tom Heinsohn, K. C. Jones and Bill Russell, who sometimes switched from center, his primary position, to forward when Conley was in the game. A talented defender and rebounder, Conley averaged 8.3 rebounds per game in the 1959-60 season while guarding the likes of the 7-1 Wilt Chamberlain.
In the years the Celtics made the playoffs, Conley would show up late for baseball’s spring training.
Many coaches and teammates supposed that playing basketball during the entire off-season would leave him in shape for spring training, but that was not the case, Conley said.
“I’d just go down there for two weeks and tell them I was ready to go, but I really wasn’t,” he said. “The muscles are so different that when you get on dirt and put cleats on, it’s like running on clay, so all these different muscles get really sore.”
Playing dual seasons allowed little time to recuperate from injuries, which often impaired his pitching. He struggled with back pain throughout his career and shoulder problems starting in 1955.
During the 1960 season, the Phillies offered Conley $20,000 to take the winter off. He made a counteroffer, which the Phillies rejected. They then traded him to the Red Sox near the end of 1960, making him the only athlete to play for three different Boston teams — the Braves, the Red Sox and the Celtics.
He retired from baseball after a disappointing 1963 season, with the close of his basketball career not far off. In 1961 he had left the Celtics to play in the American Basketball League, then moved to the Knicks of the N.B.A. the next year and retired after the 1963-64 season.
Donald Eugene Conley was born on Nov. 10, 1930, in Muskogee, Okla., to Raymond Leslie Conley and the former Eva Beatrice Brewer. After his family moved to Richland, Wash., he lettered in baseball, basketball and track at Columbia High School.
Conley entered Washington State College on a baseball scholarship in 1949. He played in the College World Series that year, after a season in which Washington State had finished 29-6 and Conley had batted .417 and won five games, with two shutouts.
He played only one season of college basketball, but in that season he was named an all-American as he helped Washington State win the Pacific Coast Northern Division, for which he was inducted into the State of Washington Sports Hall of Fame. His pitching attracted scouts from many major league teams, and he signed with the Boston Braves in 1950.
Conley started pitching in the minors in 1951, the same year he married Kathryn Dizney, who survives him. He was named minor league player of the year by The Sporting News in 1951 and again in 1953, becoming the first player to receive the honor twice. (The feat was later duplicated by Sandy Alomar Jr.)
Conley beat the Brooklyn Dodgers five times in his first season with the Braves, when the team included luminaries like Jackie Robinson and Pee Wee Reese, and pitched in three All-Star Games, winning one in 1955.
Toward the end of his career with the Red Sox, he received regular cortisone shots in his shoulder but did not tell the team, fearing his career would be over if it was known he had a sore arm. Though he won a career-high 15 games in 1962, his arm never recovered.
After his dual career, Conley moved with his wife to Foxborough, where they established the Foxboro Paper Company and ran it for 34 years before retiring to Florida. They later returned to Foxborough.
In addition to his wife and his daughter Kelly, he is survived by another daughter, Diane Kathryn Quick; a son, Gene Raymond; a sister, Billye Lynn Drew; seven grandchildren; and two great-grandchildren.
Conley’s basketball coaches, he recalled, were less concerned about his dual career than his baseball ones: “Red Auerbach used to say, ‘Well, Gene, the playoffs are over, the season’s over, now you can go down and try to get out of shape so you can pitch.’ ”