YOU CAN'T CORRECT THE BABE OFF OF THE PINNACLE:

Ladies and gentlemen, the greatest sluggers of all time *: (*Adjusting for home-field advantage, changing conditions of the game over time, and improvements in the talent poolbut not steroid use, which appears to have had little or no effect.) (Christopher Shea, April 10, 2005, Boston Globe)

[A] statistician at the University of North Carolina, Michael J. Schell, has produced what may be the most rigorous effort yet to compare baseball players from various eras. And in the process, he has offered a tantalizing suggestion that steroids may not have affected the game as much as many people assume. His data suggest that either virtually everybody is using steroids (unlikely but possible), or that the performance enhancers aren't doing much to enhance performance. A steroid-driven change in the game, Schell said in a recent interview, ''doesn't show up in an obvious way.''

Schell, a research professor at Chapel Hill, doesn't make that argument directly in his new book, ''Baseball's All-Time Best Sluggers: Adjusted Batting Performance from Strikeouts to Home Runs'' (Princeton). His only goal is the ''Holy Grail,'' as he puts it, of divining the greatest hitters everleveling the playing field across the decades so that Barry Bonds can be stacked up against Babe Ruth, Nap Lajoie, and Shoeless Joe Jackson.

In the so-called ''dead ball'' era of 1901 to 1919, the average ballplayer hit 2.3 home runs and had a batting average of .254. In the ''lively ball'' era, Ruth's prime, the numbers jumped to 7 home runs and .276. (Many people think the ball itself changed in the latter period, but most baseball historians say that the more frequent introduction of new balls during the course of a game, plus the abolition of the spitball, made most of the difference.) In today's new ''power era,'' which Schell dates back to 1993, the average player hits more than 15 home runs, with a batting average of .267.

Schell's method of leveling the historical playing field is enormously complex. (The book is not an obvious Father's Day gift - unless Dad is an engineer or truly major-league stats hound.) In devising his rankings, Schell makes three main corrections: for changes in the general conditions of the game (the jump in overall batting average during the 1920s, for example), for home-field advantage, and for improvements in the talent pool. It's only the last of these that may speak to the effect (or non-effect) of steroids.

First, to correct for shifting conditions in the game, Schell gives players credit for the degree to which they beat the average in their era. Ruth is off the charts in this respect: In 1920, the year he hit 54 home runs for the Yankees, he clouted more of them than did any other team in the league. Bonds would have to hit more than 200 home runs in a year to outpace his rivals by a similar margin.

The second correction, one of the book's major contributions, takes into account each player's home ballpark. Schell includes data, charts, and graphs on virtually every park since the dawn of the pro game. From 1912 to 1934, for example, Fenway Park was among the worst parks for power hitters in the league. With the addition of the Green Monster in left field, the park saw an explosion in doubles and triples, though it became only mildly favorable for home runs (until the mid-1980s, when further modifications evidently made it very slightly unfavorable for the long ball).

Ruth takes a hit when you consider home-field advantage: Not only was Yankee Stadium home-run friendly in the late '20s and '30s - it is no longer - but, with its short right-field fence, it also favored lefties like him. On the other hand, Fenway famously held back Ted Williams, who batted left-handed. The New York Giants slugger Mel Ott, who played in the Polo Grounds, and the Phillies' Chuck Klein, who performed in the Baker Bowl, are two high-profile players who benefited from huge home field advantages. Among active players, Schell thinks that Rockies outfielder Larry Walker owes his 1997 MVP award to Coors Field. ''It should have been [Mike] Piazza's,'' he says flatly.

Finally, taking a cue from Harvard paleontologist and baseball fan Stephen Jay Gould, Schell partly corrects for the quality of the talent pool of major-league players. Gould argued, in his 1996 book ''Full House: The Spread of Excellence from Plato to Darwin,'' that in a given arena of competition - biological or athletic - the variation in performance should decrease as the competence of organisms improves. Therefore, the fact that Ruth could blow away the competition, whereas Bonds faces many able rivals, suggests that baseball players are on average much better at power hitting today. So Schell's system gives Bonds, along with other modern sluggers, some extra credit here.