LeBron James, as of this writing, has attempted 27,307 shots in his NBA career. He has won 4 NBA championships - meaning it takes James just over 6,826 shots per championship (SPC).
Kareem attempted 28,307 shots. He won 5 rings, for an SPC of 5,661
Michael Jordan attempted 24,537 shots in his NBA career. He won 6 NBA championships - an SPC of 4,089.
Bill Russell attempted 12930 shots in his NBA career, with an SPC of 1,175.
Clearly SPC is the most accurate measure of NBA ability at the highest level. Rights are pending, but it should be considered proprietary in principle as it will inevitably change talking basketball forever.