Question: The 1974–75 Seattle SuperSonics season included which former Boston Celtics center as head coach?

<P0-S0> The 1974–75 Seattle SuperSonics season was the 8th season of the Seattle SuperSonics in the National Basketball Association (NBA). <P0-S1>  After defeating the Detroit Pistons in 3 games in the first round in a best-of-three series, the team fell to the future champions Golden State Warriors in six games. <P0-S2>  In their second season with Bill Russell as head coach and with rookies comprising half the roster, the SuperSonics finished the regular season in 4th place in the Western Conference with a 43–39 record and reached the playoffs for the first time in franchise history. <SEP> <P1-S0> The 1988–89 Boston Celtics season was the 43rd season of the Boston Celtics in the National Basketball Association (NBA). <P1-S1>  This was the first season for Jim Rodgers as head coach. <P1-S2>  Rodgers had been a Celtics assistant coach prior to this season. <P1-S3>  This year's Celtics team was severely hindered by the loss of star forward Larry Bird to a heel injury which required surgery. <P1-S4>  Bird played only six early-season games before being lost to injury. <P1-S5>  Initially, Bird was expected back in March, but it was delayed and ultimately became a season-ending injury. <P1-S6>  The results were dramatic as the Celtics, who had averaged over 60 wins per season thus far in the 1980s, fell to just 42 wins in this season. <P1-S7>  Coming into the season, the Celtics had been the Eastern Conference's #1 seed five years in a row. <P1-S8>  This season they were the #8 seed, clinching a playoff spot in the season's final game. <P1-S9>  This season included some bright spots, particularly the emergence of guard Reggie Lewis, who had been only a minimal bench contributor in his rookie season of 1987-88, but averaged nearly 20 points per game as a starter in 1988-89. <SEP> <P2-S0> The 1973–74 Seattle SuperSonics season was the 7th season of the Seattle SuperSonics in the National Basketball Association (NBA). <P2-S1>  Following the resignation of Lenny Wilkens as a head coach after the 1971–72 season and a poor campaign in the 1972–73 season that saw the departure of general manager Bob Houbregs, the Sonics hired Boston Celtics' stalwart Bill Russell as head coach and general manager. <P2-S2>  With Russell at the helm, the team finished in 6th place in the Western Conference with a 36–46 record. <P2-S3>  The Sonics' home court, Seattle Center Coliseum, was the venue for the 1974 NBA All-Star Game. <SEP> <P3-S0>  Russell played center for the Boston Celtics of the National Basketball Association (NBA) from 1956 to 1969. <P3-S1>  A five-time NBA Most Valuable Player and a twelve-time All-Star, he was the centerpiece of the Celtics dynasty, winning eleven NBA championships during his thirteen-year career. <P3-S2>  Russell holds the record for the most championships won by an athlete in a North American sports league (tied with Henri Richard of the National Hockey League). <P3-S3>  Before his professional career, Russell led the University of San Francisco to two consecutive NCAA championships (1955, 1956), and he captained the gold-medal winning U.S. national basketball team at the 1956 Summer Olympics. <P3-S4> William Felton Russell (born February 12, 1934) is an American retired professional basketball player.