CONTRASTS: Because GMs now know better, the guy on the left (Youkilis) is starting for the Red Sox while the guy on the right (Hillenbrand) is riding the pine in Los Angeles.

It’s become the creationism v. evolution argument of baseball. There are those who prefer the old school approach – looking at a guy’s raw skill along with things like “grit,” “hustle” and determination – and those who prefer a numbers-based approach, which attempts to assign a different kind of value to things that happen on a baseball field. The latter practice is commonly called “sabermetrics,” after the Society for American Baseball Research (or SABR,) and if sports columns, books, talk radio, television, and interpersonal conversations are to be believed, even now, 30 years after its unofficial “founding,” it remains one of the most misunderstood concepts in sports. Fortunately, unlike creationism and evolution, there are some pretty well-defined answers to this. So here, in short, is a quick explanation some of the common misconceptions about what sabermetrics are all about.

Myth #1: These stats are a “new” concept
Not really. Back in 1977, Bill James, a security guard with a math jones, studied the numbers and compiled the information in the book The Bill James Baseball Abstract. Given the audience James found almost immediately, it’s safe to assume he wasn't the only one thinking of it at the time. As James's research proved, this information was always out there; it was just a matter of looking in the right places. Events that “don't show up in the box scores” actually do, for the most part (except for defensive plays; more on that in a second). To take on-base percentage as an example, a hitter's ability to avoid making an out has always been something measurable — people simply weren't really measuring or placing value on it.

Myth #2: These stats are redundant
It's a common tenet of the SABR-haters: “hey, I love stats, but back in my day, we used a little thing called batting average and runs batted in!” But neither of those statistics really paint a full picture of a player's actual value.

Batting average is, ultimately, a hollow stat. Simplify it this way: the worst thing a batter can do is get an out. Batting average may account for each time a batter gets a hit, but it doesn’t measure how well he avoids outs. It’s a key difference over the course of a season. While there isn't a huge difference in terms of number of hits between a .300 hitter and a .260 hitter, there is a bigger difference between the number of times reached base by a batter with .320 on-base percentage and a guy with a .360 on-base percentage. Slugging percentage, meanwhile, measures total bases per at-bat. If a guy just comes up and hits singles every time, he’ll have some value to your team, but much less than a guy who mixes in frequent doubles and home runs. Use the smell test: would you rather have Mark Loretta (.285 batting average with a .361 slugging percentage last year) or Dan Uggla (.282, .480)? You’d take Uggla every time. Obviously.

The common rejoinder is “well, yeah, but Uggla hit 27 home runs and had 90 RBIs.” And we’re with you on the first part; home runs are good. They’re great: they’re the best possible outcome on any given pitch. But RBIs don’t really tell you much of anything. They’re more of a team stat. A player gets credited with an RBI for, essentially, getting a hit with a runner on base. But what did he really do? Did he will that guy to get on base before him? No. He just collected a hit — sometimes even just made an out — while someone else motored in to home. What control over that does anyone really have?

Myth #3: Sabermetrics = On-base percentage worship
This myth originated out of the media hype generated by the book Moneyball, in which Michael Lewis followed Oakland A’s general manager Billy Beane around during the 2002 season. The book was intended to demonstrate how Beane used advanced stats to expose market inefficiencies and sign valuable players at a discounted price for his small market team. In 2002, that meant going for guys who had strong abilities at getting on base. In 2007, it means something different.

Baseball is a changing game. Five years ago, a lot of people running baseball teams — and the experts who covered them — didn’t pay attention to these traits. Now, with some exceptions, most teams do have a consideration for this kind of skill, and players have been forced to adapt. The game reflects the new way of thinking. Hence why Kevin Youkilis (lifetime on-base percentage: .378) has a starting job with a big-league team and Shea Hillenbrand (lifetime on-base percentage: .324) does not. So with on-base percentage (or OPS, the sum total of a player’s on-base and slugging averages) having already taken hold, the statheads have to find a new way to differentiate orders of magnitude between players.