Throughout his San Antonio career — which he began as David Robinson‘s sidekick, then continued as star of the team and now has progressed to elder statesman with reduced minutes — Duncan has been remarkably consistent in his on-court production. Per 36 minutes, Duncan has never taken fewer than 14 shots from the field in a season or more than 17; he’s never hit fewer than seven or more than 8.5; he’s never scored more than 22.6 points per game or fewer than 17.1. His blocks per 36 minutes have ranged from a low of 1.7 to a high, this year, of 3.2. And his rebounds per 36 minutes have ranged from 10.5 to 12.2. While he’s on the court, Duncan at 36 is almost exactly the same player — or at least almost exactly as productive — as he was at 21, and at 28.
Even in the smaller sample size of the playoffs through the first two rounds, Duncan’s productivity has been remarkably consistent, aside from a muted performance in San Antonio’s first-round exit two years ago against Memphis — incidentally, also its opponent in the next round this spring. Aside from that blip, Duncan’s field-goal attempts per 36 minutes have averaged between 13.5 and 17.6 in each of his other 14 postseasons; his made field goals have ranged between 7 and 9 per 36 minutes; and his points have ranged from 17.9 to 24.5 per 36 minutes.
In every year of his 16-year career, Duncan has played at least 1,500 minutes and appeared in at least 45 games. Four players who debuted within three years of Duncan also each have at least 16 seasons with as many appearances and minutes: Kevin Garnett, Ray Allen, Jason Kidd and Kobe Bryant. They are, along with Duncan, the most durable and consistent players of their generation.
In some respects, Duncan has been the most consistent of the five veterans. Feel free to skip the rest of this paragraph if you don’t want the details. To calculate consistency for these veterans, I analyzed their per-36-minute production, limiting the analysis to their age-36 season and earlier, and to years in which they played at least 1,500 minutes and appeared in at least 45 games. (So Kidd, the oldest of the group, doesn’t appear less consistent for his decline in recent years.) For each player, for a range of stats, I calculated the standard deviation of that stat over those full, pre-37 seasons of his. Standard deviation — a measure of how much a quantity varies — is a good start. But standard deviation can confuse consistency with a flatline: Duncan has between 0 and 0.1 three-pointers per 36 minutes throughout his career, which isn’t a sign of consistent three-point shooting so much as it is a sign of consistent absence of three-point shooting. So I divided standard deviation by the average, to get what’s called the coefficient of variation. The lower the coefficient of variation, the less a player’s performance varied from season to season, relative to his usual, average performance.
By this measure, Duncan has been by far the steadiest of the five veterans in field goals taken, field goals made, points, blocks and rebounds. In a few other categories — field-goal percentage, free throws taken and made, and turnovers — he’s edged only by Bryant. From year to year in the postseason, Duncan also leads the group in consistency in the same five categories that he does in the regular season.