Davey Johnson will probably never be remembered as one of baseball’s all-time greats. Sure, he was a very good second baseman. And yes, he was probably an even better manager. But nothing sticks out about him as an immortal of the MLB, like Babe Ruth or Hank Aaron or Walter Johnson.

But Johnson’s impact on baseball might just be bigger than any of those legends.

The evidence? Look at any major league front office. Almost every acquisition and a number of in-game decisions are made on the basis of sabermetrics. Sabermetrics are defined as “the search for objective knowledge about baseball” by Bill James, the man who is often credited with founding this school of thought. The (very) general idea behind sabermetrics is to empirically analyze baseball for useful statistics and data. Baseball teams use many of the statistics that originate from sabermetrics to determine which players to acquire, or who to pinch hit in a given situation, or analyze who might be overperforming or underperforming.

But what does Johnson have to do with sabermetrics? Quite a lot.

The earliest sabermetricians

The idea of using statistics to measure baseball player’s usefulness is nothing new – it’s been around for more than a hundred years (which is why Fangraphs has baseball data going all the way back to 1876). Every fan is familiar with the basic statistics like batting average, pitching wins, and ERA. But the development of new statistics was effectively stagnant before Earnshaw Cook came along. Cook wrote a little book called Percentage Baseball, which took a hard look at the statistics of baseball, and dared to suggest that there was something wrong with them. It should have turned the baseball world on its ear – here, the statistics were wrong! There’s a great big book of proof!

But there were two things wrong with Percentage Baseball. Number one: it was far too wordy for any manager to take seriously. Cook himself said that “Baseball … furnishes a classic example of the utter contempt of its unsophisticated protagonists for the scientific method.” In other words, no manager in baseball thought Percentage Baseball was worth the paper on which it was printed.

Number two: it was pretty wrong. Bill James is quoted as saying “Cook knew everything about statistics and nothing at all about baseball–and for that reasons, all of his answers are wrong, all of his methods useless.” Cook promised that his methods could add 250 runs to an existing team, which was rightfully absurd.

But while his early attempt at sabermetrics may have been misguided and initially ignored, it sowed the seeds of rebellion in baseball statistics.

The revolution begins

While no manager took Percentage Baseball seriously when it first came out, some players did – notably a second baseman for the Baltimore Orioles named Davey Johnson. Johnson read it and loved it, to the point where he actually sought out Cook and became friends with him. Johnson was not your typical major leaguer – not only was he college educated, he had a degree in mathematics. If anyone would be lured into Cook’s world of math, baseball, and rebellion, it would be Johnson.

Johnson was quick to try to put his ideas into action. The owner of the Orioles at the time was Jerry Hofberger, who was chairman of the National Brewery. Johnson managed to convince Hofberger to lend him the brewery’s computer to use at night so that he could write a baseball simulation in it. Johnson played around with the numbers, came up with some data, and tried to convince the Orioles’ manager to let him bat second. It didn’t fly with the manager, but the idea of using computers and advanced statistics to organize lineups never left Johnson’s mind.

Success on paper starts to translate

Years later, after Johnson’s playing career came to a close, Johnson was hired to manage the fledgling New York Mets. In 1983, the Mets had finished with an atrocious 68-94 record. The Mets had simply looked bad. Johnson was called up from the Mets’ AAA affiliate, the Tidewater Tides to turn the club around.

Johnson had finally gotten his own computer and had used it to write up his lineups in AAA. Gary Carter would later write, “Davey managed by the numbers…literally. He was a computer whiz who could pull up more baseball statistics on his screen than most of us knew existed. I liked Davey, but I didn’t care much for his computer.” He brought this same strategy to the ’84 Mets.

Obviously, expectations aren’t that high if you just finished off a season in 6th place. But whatever was expected of Johnson in ’84 was blown away. The Mets suddenly reversed their woes of last year and turned in a 90-72 record. What was more impressive, however, was their Pythagorean record (for the uninitiated, a Pythagorean record is what a team’s record should have looked like based on how many runs the team scored versus how many runs the team allowed). Their Pythagorean record was 78-84. The Mets should have been a mediocre team in ’84, but they dramatically overperformed. But aside from rookie Doc Gooden, there was little difference between the team of ’83 and ’84 – did Johnson make the difference?

It’s difficult to say for certain that Johnson was solely responsible for the Mets’ turnaround. But with his unorthodox management strategy and instant success, other teams began to take notice. Two years later, the Mets won the World Series, and sabermetrics had a weak foothold in baseball.

It would take a while longer for sabermetrics to be widely used in baseball. It wasn’t until Billy Beane‘s Oakland Athletics that most front offices converted to the church of sabermetrics (of note – Beane was drafted by the Mets and spent some time as a player under Johnson – coincidence?). But Johnson was really the first to take sabermetric principles and apply them in baseball. His success would signal how useful sabermetrics really could be. And so Johnson’s experiment opened the doors for the baseball we see today.