A three-time All-Star, he won the Cy Young Award in 1977, the first American League reliever so honored.

Lyle co-authored, with Peter Golenbock, The Bronx Zoo, a 1979 tell-all book that chronicled the dissension within the Yankees in its World Series Championship seasons of 1977 and 1978.

Lyle is credited, alongside Rollie Fingers, with expanding the role and importance of the reliever in professional baseball beginning in the 1970s.

[1] He progressed up the Red Sox farm system as a relief pitcher, with stops in Winston-Salem in 1965, Pittsfield in 1966 and Toronto in the first half of 1967.

[3] It was during his time at Pittsfield that he picked up the slider, a pitch that was introduced to him by Ted Williams at spring training prior to that season.

[1] Lyle pitched two scoreless innings to close out a 4–3 Red Sox loss to the California Angels in his major-league debut at Anaheim Stadium on July 4.

[5] He recorded his first career save twelve days later on July 16 in Boston's 9–5 victory over the Detroit Tigers at Fenway Park.

[7] He ended his rookie campaign with 27 mound appearances, a 1–2 record, five saves and a 2.28 earned run average (ERA).

[8] During spring training prior to the 1972 season on March 22, Lyle was traded to the New York Yankees for Danny Cater and a player to be named later (Mario Guerrero).

To this end they signed Pittsburgh Pirates' reliever Rich Gossage, who had been an All-Star the previous three years and had led the American League in saves while with the Chicago White Sox in 1975.

On November 10, 1978, the Yankees traded him to the Rangers along with catcher Mike Heath, pitchers Larry McCall and Dave Rajsich, and minor league shortstop Domingo Ramos in exchange for outfielder Juan Beníquez, pitchers Mike Griffin, Paul Mirabella, and Dave Righetti, and minor league outfielder Greg Jemison.

Lyle signed a contract with the Rangers shortly after he was acquired, with the intention of him finishing his playing career in Texas.

He was nearly dealt along with Johnny Grubb from the Rangers to the Philadelphia Phillies for Tug McGraw, Bake McBride and Larry Christenson at the 1979 Winter Meetings in Toronto, but the proposed transaction was never executed because, although Lyle did not have a no-trade clause negotiated into the deal he had signed after being traded to the Rangers, the two sides had agreed to defer a total of $500,000 that was to be paid to him over ten years as his salary for becoming an analyst on the team's television broadcasts once Lyle retired and they could not strike an agreement regarding that.

Lyle was dealt to the Phillies on September 13 in a transaction that was completed when Kevin Saucier was sent to the Rangers two months later on November 19.

In 1998, Lyle became the first manager of the Somerset Patriots, an independent baseball league team based in Bridgewater, New Jersey.

[16] A noted clubhouse prankster in his playing days, Lyle was known for sneaking into the locker room during games to sit naked on birthday cakes prepared for teammates, leaving the imprint of his posterior on the frosting.

[18] As a world-class practical joker, Lyle engaged in creative pranks like putting goldfish in the dugout water cooler and ordering pizzas to be delivered to the other team's bullpen.