I mean in terms of comparison to Tom Chambers who had all the "athletic" stuff people think of...high jumping, lots of dunks, good speed for position, etc.
Bird was a master at controlling his energy expenditure. LeBron, Duncan, and peak-2003ish-McGrady are recent players who have had that Bird-like mode where they're impacting the game heavily, while not really exerting themselves too much in terms of flying all over the court, making unnecessary movements, etc.