During Bill Russell’s 13 years with the Celtics, Boston allowed the fewest points per possession in the league 12 times, and they still have the four most dominant seasons ever by defensive rating (in consecutive years)
Now, this is probably actually crazier than it sounds.
As an aside, defensive rating = points allowed per 100 possessions
To help sort of illustrate his defensive impact, I decided to write the Celtics’ defensive ratings every season from Bob Cousy being drafted, to Russell’s career, to another all-time great defensive center in MVP Dave Cowens running the show for Boston. I bet (even without the 12 in 13 context) one could guess which years Russell played. None of this factors in the Celtics likely being better in the playoffs where they won their 11 titles.
10th, 4th, 8th, 8th, 6th, 1st, 1st, 1st, 1st, 1st, 1st (3rd best ever relative to the league), 1st (4th best ever relative to the league), 1st (best ever relative to the league), 1st (second best ever relative to the league), 1st, 1st, 2nd, 1st, 8th, 3rd, 5th, 1st, 6th, 3rd, 3rd, 7th, 12th, 19th, 4th (also Bird’s first year)
Statistically, the 1964 Celtics are the best defensive team ever, allowing 10.8 fewer points per projected 100 possessions (it’s an approximate, because exact turnover and offensive rebounding numbers didn’t exist). The 61-65 Celtics are all of the greatest defenses ever.
The only team to get remotely close in the last 20 years is the current OKC Thunder. Last year, their defensive rating was exactly 7 point better than league average (114.5 vs 107.5). This year they’re actually 9.1 points better so far, but started off better last year as well and weren’t able to maintain it over a full season.
Right now, they’re on pace for the third most dominant season ever behind the 64 and 65 Celtics, but again, only half a season.
Out of all the superstars in NBA history, the closest to matching those feats would be Tim Duncan (with nobody nipping at his heels), who led the NBA in defensive rating on the Spurs six times.
They had the best defensive rating in 99, 01, 04, 05, 06, and 16. In 04, the Spurs had one of the 10 most dominant defensive ratings relative to the league ever. Now, rightly or wrongly, three different teammates finished higher in DPOY voting than Duncan during those stretches (David Robinson, Bruce Bowen, Kawhi) and the Spurs also had the best defensive rating the year after he retired.
One could point out that there were fewer teams when Russell played, and they’d be right, but they’d forget that Russell’s Celtics were not barely edging out other teams in the league and still currently have the four best defenses ever statistically. They also have eight in the top 20, which makes up more than 60% of Russell’s career.
People often call Bill Russell the most dominant defender ever in his time, but these numbers bring some context into just how indisputably true that is. He dominated defensively like few have offensively.