I don’t often do this, but I am going to warn some of you away from this post. It is about baseball. Worse, it’s about baseball statistics, and it’s kind of a deep dive. If these things don’t interest you, I’d suggest you stop reading. Feel free to browse my archives. I’ve got posts about all sorts of stuff. I’m sure there’s something here that’ll interest you. But this might not be it…

I spend a fair amount of my down time perusing the baseball threads on Facebook and other social media platforms, and have encountered again and again arguments over modern statistical innovations that are designed to facilitate comparisons of players across leagues and eras. A couple of confessions up front: First, I tend to like these innovations. In my view, statistics like Wins Above Replacement (WAR, which measures a player’s offensive and defensive value above that of a generic replacement player at the same position), OPS+ (which compares a player’s on-base and slugging percentages to his league’s average), ERA+ (which does the same with pitchers’ earned run averages) are enormously helpful in most conversations about the relative merits of players who didn’t play at exactly the same time, at exactly the same position, in exactly the same home park. Second, I fully understand why some baseball fans HATE these very same statistics. And third, I am NOT a mathematician. Not even close. I write fantasy and science fiction for a living. So, while I can say much about what these new statistics do for our understanding of baseball, I cannot explain to you how they are derived. For that, I would suggest this article at Baseball-Reference.com.

One of the most common complaints I read and hear about the new statistics, WAR in particular, is that they are “made-up” stats. As if other statistics occur naturally in the wild… Of course, all statistics are made up. But I understand what critics of the new stats are getting at. When I was growing up, staring at the reverse side of baseball cards, making sense of the stats listed there back in the day, the math behind the numbers we used to judge a player’s value was quite straightforward. Home runs? Runs batted in? Runs scored? Hits? Doubles? Triples? These were simple totals. Count ‘em up and you’ve got the information you need. Batting average was a simple calculation: the player’s number of hits divided by his at-bats. 150 hits in 500 at-bats yields a .300 batting average. Even earned run average made sense, though it was a bit more demanding: Divide a pitcher’s innings pitched by 9 (the number of innings in a game), and then divide that number into the number of earned runs the pitcher allowed. 198 innings pitched and 66 earned runs allowed yields an ERA of 3.00. Easy stuff.

The new stats are way, WAY more complicated. So much so that they seem utterly opaque. The average fan, who likely doesn’t possess a Ph.D. in arithmetic, can’t possibly calculate WAR or ERA+ or OPS+ on their own. Instead, we have to take the word of those who do the calculations for us. I don’t like that, and I understand why many are reluctant to trust the accuracy of stats they can’t replicate themselves. The problem with this argument is, as I said earlier, that even the simplest of calculations are “made up.” For example, currently a sacrifice fly—a fly ball out on which a runner tags up and scores from third (or second) base—does not count as an at-bat for a batter. He gets a run batted in, and the out does not impact his batting average. But this rule has been changed many times over the past century and a quarter, most recently in 1954, when the current rule went back into effect. This underscores that batting average is a “made-up” stat, too, one that has changed several times over the years.

More to the point, the old statistical slash lines—batting average, home runs, RBIs—ignore numbers critical to understanding a player’s contributions to his team. How many walks does a batter draw? How often does he get on base? How often does he ground into double plays? How are his stats impacted by the stadium in which he plays most of his games? How are they impacted by the overall offensive context of the time he is/was active? How good or bad is he as a defensive player? How much is a pitcher’s performance influenced by his home stadium and the defense playing behind him? All of these factors help to shape a player’s WAR, his OPS+, and his ERA+. The portrait of a player offered by modern statistics is far more complete and accurate than the old stats could provide.

Why is all this information valuable? Well, let’s look at a real-life comparison that demonstrates the power and accuracy of these new statistics.

In 1973, the American League’s Most Valuable Player was Reggie Jackson of the Oakland A’s. That year, Reggie hit 32 home runs, drove in 117 runs, and batted .293. His home run and RBI totals led the league (as did the 99 runs he scored). He also led the league with a .531 slugging percentage. He was the unanimous MVP choice.

Five years later, in 1978, the American League’s MVP was Jim Rice of the Boston Red Sox. Rice hit 46 home runs, drove in 139, and batted .315. His home run and RBI totals led the league, as did his 15 triples and 213 total hits. Rice also led the league with a slugging percentage of .600. He wasn’t the unanimous choice for league MVP, but the vote was not particularly close.

So, who had the better season? Based on the raw numbers, it would be easy to conclude that Rice did. His batting average is 20 points higher. His slugging percentage is 70 points higher. He had 14 more homers, twenty more RBIs, and 55 more hits.

Yet, their numbers are closer than one might think. Reggie’s WAR for 1973 was actually slightly higher than Rice’s in 1978: 7.8 to 7.6. Reggie’s OPS+ was higher as well, 161 to 157. And this, I know, is the sort of thing that drives some fans crazy. How can their numbers look like that? How can all of Rice’s statistical advantages result in a disadvantage in the newer stats? Good questions. Good questions that, as it happens, have very good answers.

In 1973, Reggie walked 76 times and got on base at a .383 clip. In 1978, Rice walked 58 times and got on base at a rate of .370. Despite Rice’s better batting average, he actually got on base less frequently than Reggie did. Further, Reggie struck out fewer times and grounded into slightly fewer double plays. He stole three times as many bases as Rice, with a far better success rate. And (many will be surprised to read this) 1973 Reggie was far more effective on defense than 1978 Rice. Digging a bit deeper, Reggie was responsible for making 409 outs as a batter in 1973, ranking 39^th in the league. In 1978, Rice was responsible for a whopping 490 outs made, which ranked him fourth. Despite having a great season, he made more outs than all but four American League batters. Finally, the 1978 iteration of Jim Rice was helped enormously by his home stadium, Fenway Park. He hit .361 at home and had 10 more home runs in Fenway than he did on the road. In 1973, Reggie was hurt by playing half his games in Oakland Coliseum. His batting average at home was .259, compared with .321 on the road. He actually hit a few more home runs in Oakland, but all his other numbers were far worse at home than on the road.

So, compared with Jim Rice in 1978, Reggie Jackson in 1973 made far fewer outs, played in a far less offense-friendly home park, got on base more often, and was better on the bases and in the field. All of this taken together is not reflected at all in the old-fashioned slash line of batting average, home runs, RBIs. But it is fully reflected in the new statistics, WAR and OPS+.

Why does this matter? Well, in a world plagued by war and poverty, corruption and cruelty, it doesn’t matter at all. Not a whit. But for baseball fans, who just love to debate the merits of players from different eras, different leagues, different positions, it can matter a great deal. Who was better, Mantle or Mays, Koufax or Kershaw, Gehrig or Pujols? Those questions still animate conversations, but now we have far more precise tools with which to make our points.

Yeah, so maybe it doesn’t matter at all.

But on a cold, rainy, dark November day, it sure is fun to think about this stuff instead of wars (the real kind), poverty, and the rest.

Thanks for reading.