This week, the Baseball Hall of Fame will announce a new class of inductees, setting off rounds of celebrations — and debates. Fans will argue over whether Mariano Rivera deserves unanimous approval, or whether the use of performance-enhancing drugs should permanently block the enshrinement of Barry Bonds.

Oddly, amid these debates, one of the Hall of Fame’s key omissions is likely to be overlooked. How is it that it has left out — and perhaps not even discussed — the man who has had the greatest influence on baseball in the last 40 years, who has changed how the game is understood, how it is enjoyed and even how it is played? I’m talking about the statistician and historian Bill James.

A graduate of the University of Kansas, James began his professional involvement with baseball in the late ’70s, while working nights as a security guard at a cannery. When not foiling pork-and-bean burglaries, he used his free time to record and analyze baseball statistics. He had a quirky curiosity that led him to ask offbeat questions, whose answers he extracted from the numbers he kept. He wasn’t afraid to deflate reputations or debunk conventional wisdom. He turned his findings into articles, and eventually best-selling books. His writing was smart, funny, contentious, and unlike anything fans had ever read.

It may be hard for younger fans to grasp how innumerate baseball was. There were homers and R.B.I.s and batting averages for hitters; wins and losses and E.R.A.s for pitchers. Teams had winning and losing streaks. Instead of analysts, broadcasts had color commentators.