Requirements: Five seasons and 5,000 minutes; or fewer seasons and 7,000 minutes.
Honorable mention: Danny Ainge, Reggie Lewis, Dennis Johnson, Satch Sanders. Yep, that's who didn't make the cut.
20. Frank Ramsey
Ramsey was the sixth man on the early Bill Russell Celtics teams, and retired with 7 championship rings. He averaged 13.4 points and 5.5 rebounds over nine seasons.
19. Paul Silas
Power Forward, 1973-1976
A terrific defensive forward, Silas averaged a double-double in each of his 4 seasons in Boston.
18. Bailey Howell
The Celtics stole Howell from Baltimore for backup center Mel Counts, and he averaged 19+ ppg in each of his first three seasons in Boston. Howell had a down year in 1970 (the first post-Russell season), and was left unprotected in the 1970 expansion draft.
17. Jo Jo White
Shooting Guard, 1970-1979
White had 7 straight seasons of 18+ ppg, and won the 1976 Finals MVP. White was a big-game player; he averaged 21.5 ppg in the postseason, and shot slightly better, too.
16. Tommy Heinsohn
Power Forward, 1957-1965
Heinsohn won the 1957 ROY over Bill Russell, in large part because Russell skipped the early part of the season to play in the Olympics. Heinsohn was an unapologetic gunner who shot only .405 over a 9-year career, averaging 18.6 points on 18 shot attempts per game.
15. Don Nelson
Small Forward, 1966-1976
Nelson was an important piece of 5 championship Celtics squads from 1966-1976. He never averaged more than 28 minutes in a season, but still managed to put up 15 points and 7 boards in 1970. He hit a huge shot to close out the Lakers in Game 7 of the 1969 Finals.
14. Rajon Rondo
Point Guard, 2007-
Rondo is only 26 years old, already has a championship ring, and has led the league in assists and steals. He’s a terrific postseason player, too. If he had a jump shot, he’d be unstoppable.
13. Bill Sharman
Shooting Guard, 1952-1961
Sharman is the only person to coach an ABL, ABA, and NBA champion (1962 Cleveland Pipers, 1971 Utah Stars, 1972 Lakers). Sharman was also a minor-league baseball player in the Brooklyn Dodgers system, and a pretty good one (he hit .281 in four seasons). He played both sports simultaneously until 1955. His career shooting percentages are .426/.883, which are pretty exceptional for a guard in the 1950s. He led the league in FT% seven times.
12. Ray Allen
Shooting Guard, 2008-2012
Allen played 5 late-career seasons in Boston, averaging 16-18 ppg, and generally shooting the lights out. While pure shooters can last forever if they avoid significant injuries (see Reggie Miller), I was a little surprised at how well the recent and current Celtics stacked up against the all-time greats.
11. Bob Cousy
Point Guard, 1951-1963
Yes, Bob Cousy revolutionized the point guard position, and yes, he was the Jason Kidd of the 1950s (right down to the .375 FG%). Not everyone will agree, but I don't think Cousy-- and Sharman, see above-- faced the level of competition that modern players do. Cousy piled up numbers in a mostly-white league that had only 8 teams for half of his career.
10. Kevin Garnett
Power Forward, 2008-
Garnett is the defensive anchor of the current team, and also has a terrific jump shot and passing skills for a guy who's nearly 7'0". Like Allen, Garnett accepted a reduced role in Boston, and was rewarded with a championship in his first season.
9. Cedric Maxwell
Small Forward, 1978-1985
"Cornbread" is probably the only player to win a Finals MVP but never make an All-Star team. Maxwell had a couple of terrific seasons before Larry Bird arrived, and was a key piece of the 1981 and 1984 teams, before being traded for Bill Walton after the 1985 season.
8. Sam Jones
Shooting Guard, 1958-1969
Jones arrived on the Celtics the year after Bill Russell, and by 1961 was the team’s second-best player. Jones peaked in 1965, averaging nearly 26 points and 5 rebounds. Jones shot .456/.803 for his career, well above league averages, and had a reputation as a terrific big-game player. One of the Celtics’ advantages in this era was their college scouting: Jones came from North Carolina Central, which never produced another notable NBA player.
7. Dave Cowens
Cowens was an excellent rebounder and passer, and in his first few years in the league, a great defensive player. He played on two championship teams, and topped 20 ppg twice (and 15 rebounds five times). Cowens, like Michael Jordan, had three retirements, taking off the first two months of the 1977 season, then sitting out 1981 and 1982, and retiring for good after a 40-game comeback with the '83 Bucks.
6. Robert Parish
Having Parish as a third or fourth banana on the 1980s Celts was an almost unfair accumulation of talent that isn’t possible today thanks to the salary cap, and most teams’ poor understanding of how it works. Parish averaged a double-double in ten different seasons, and was called "Chief" after the character from "One Flew Over the Cuckoo's Nest."
5. Paul Pierce
Small Forward, 1999-
Pierce has developed into one of the league's most feared clutch shooters, and has been the primary scoring option for the 2008-2012 "Big Three" team. Pierce has improved his scoring efficiency as he got older (and less athletic); I wonder if Doc Rivers' coaching is responsible for that. Young Paul Pierce spent a few seasons in a battle with Antoine Walker over who could take more bad shots. Pierce didn't win that contest, but he tried.
4. John Havlicek
Small Forward, 1963-1978
Havlicek was an all-around star: a great defender, and also an excellent passer, as the Celtics found out when the retirement of K.C. Jones forced Havlicek into more ballhandling duties. He rarely missed a game or even came out of one, playing an incredible 4215 regular season and playoff minutes in 1972. His statistical peak occurred the year before, when he averaged a 28.9/9.0/7.5.
3. Kevin McHale
Power Forward, 1981-1993
Here’s a good question. What made the Celtics use a player as great as Kevin McHale in a sixth man role for most of his career? My theory is that McHale was very foul-prone as a young player. So even though he was a better player than starting forward Cedric Maxwell by his third season, he came off the bench until the Celtics traded Maxwell. This probably kept McHale from picking up too many cheap fouls early in games, and allowed him to play more aggressively in the fourth quarter. In his first year as a starter, 1986, he put up 24.9 points and 8.6 boards in the playoffs en route to the Celtics’ third title of the decade. His career year was 1987, when he averaged 26 points and 9.9 boards despite playing the last few weeks and the playoffs on a broken foot.
2. Bill Russell
Russell was the greatest defensive player to ever play the game.
1. Larry Bird
Bird joined the Celtics in 1980, and they jumped from 29 wins to 61 and a conference finals loss to the Sixers. In Bird's second season, the Celtics won it all, and would win again in 1984 and 1986. Bird averaged-- for his whole career-- an unholy 24-10-6 on .496/.376/.886 shooting. His career was shortened by injuries to his feet and back; Bird had only one season where he was reasonably healthy after age 31.
Next up: The NBA's oldest continuous franchise, the Fort Wayne / Detroit Pistons, who played their first NBL season in 1942.