It’s okay to be mystified by linear weights

Everywhere you turn this offseason, you can find a primer on all things sabermetric. Here are a couple good ones on wOBA and UZR. Here’s a neat one on FIP. And heck, here’s an entire online course on the state of the art. There’s just so much good work being done by so many good minds right now that jumping on this train can seem a little scary. The various introductions written for new adopters fill an important niche, but I’m not sure they reach the demographic we’re most concerned with winning over.

At our best, we’re open-minded folks who take a reason- and logic-based approach to the game we love. At our worst, we’re an avant garde gang of know-it-all cyber-bullies, ready and eager to viciously pounce on any Luddite who still worships at the altar of the run batted in. And I think we’re at our worst more than we’d like to acknowledge.

Our arrogance comes from the strength of our position; we’re right about baseball and we know it. The problem is that things have become almost cultish; our alphabet-soup language poses a formidable barrier to entering the club. And that’s where these primers come in. If we can walk people through the silliness of pitcher wins and ERA, they’ll greet FIP with open arms. That’s the plan.

But I’m not sure it works as elegantly as we’d like. I believe we’ve reached a sort of saturation point with advanced stats. Most anyone who wants to know about WAR is already plugged in. And the primers, while enjoyable, accurate, and insightful, are still lessons. I don’t know about the rest of you, but I got into sabermetrics because I enjoyed discovery. There’s a fine line between learning and being taught, and the former is much more enjoyable than the latter.

What’s more, at the end of the day, do we really care if the people we watch the game with know the differences between UZR and Dewan Plus/Minus? Does it matter if they can discuss the merits and flaws of SIERA? Do our friends need to carry run expectancy charts in their briefcases?

I say no. What’s important about sabermetrics isn’t the statistics, but the approach to the game. I believe a fan can be educated and informed without having command of the advanced stats. What matters are these three principles:

1. Baseball is an individual sport.

This is perhaps the most important concept a person can understand about baseball. Once one accepts that baseball is an individual sport, all of the context-dependent noise goes away. Pitching wins, runs batted in and even errors can be tossed aside. The key here isn’t that wins, RBIs and fielding percentage aren’t indicative of skill. The point is we can do better.

Understanding that baseball is an individual sport unlocks OBP and the entire suite of fielding-independent pitching statistics. What matters isn’t that our friends know how to properly weigh OBP compared to SLG; it’s more than enough to recognize that not making outs is the single most important thing a hitter can be good at. And the same goes for pitching—we don’t care if people we watch the game with can recite Voros McCracken’s groundbreaking hypothesis. What counts is if people recognize that pitchers who strike many out, walk few, and surrender a small number of home runs are awesome.

2. Luck is huge.

This might be the toughest hurdle for some. There’s no more frustrating an event in baseball than when you’re yelling at a manager, exhorting him to make the right move, the manager makes the right move, and the outcome is still negative. That good decisions can have bad outcomes is annoying enough. The even bitterer pill for so many to swallow is that a good decision with a bad outcome was still, you know, a good decision.

Eschewing notions of karma, superstition, and players being “due” is vital to understanding today’s top-shelf baseball analysis. One of the best things about baseball is that it is played often enough (and for long enough) that statistically significant sample sizes build up. From there, we can predict what will happen in the future with a relatively high degree of accuracy. While knowing precisely how to treat a player’s performance in the Pacific Coast League isn’t required, understanding that thousands of at-bats matter more than what happened last night is key.

3. It’s all economics.

Every single decision made in baseball is a trade-off. Some decisions are made instinctively after years of experience and coaching—does the benefit of trying to turn two outweigh the possibility of getting neither out? Other decisions are made with much more contemplation—does a hotshot amateur player’s asking price match our ability to pay closely enough to mitigate the risk of not being able to sign him? No decisions in a proper baseball organization are made in a vacuum.

Recognizing that strategies and tactics at both in-game and organizational levels (and everywhere in between) have tangible consequences is an important step. Practically, this concerns the value of an out, and how rarely one is worth surrendering. On a broader scale, it has to do with judging a team not by its performance against the rest of baseball, but on how efficiently it uses its resources compared to its peers. What matters isn’t how the free agent that got away does next season, but whether the decision not to sign him was correct given the information available at the time.

So where does this leave us?

A Hardball Times Update
Goodbye for now.

Accepting the principles above will make any baseball fan intuitively aware of the nuanced approach sabermetricians take to the game, regardless of an understanding of our language. Very recently, Baseball Prospectus’ Will Carroll urged:

We need a gateway drug. We need an educational initiative. We need a PR campaign. We need to evangelize. We need to market. We need to explain, over and over. We need to find ways to engage and educate each and every baseball consumer who’s willing to listen and wants to learn. We need to fight the anti-logic bias this country has and we need to do it soon.

Primers are a wonderful tool for accomplishing that goal, but they’re most effective in the hands of someone who wants to be taught. I submit that the threshold step isn’t giving someone the keys to wOBA or xFIP, but rather appealing to their instincts. And to me, a simply magnificent place to start has been right under our noses for several years:

It’s Fire Joe Morgan’s Glossary.

Is it outdated? Absolutely. WARP-3, EqA, and DERA aren’t what they once were. And a fan doesn’t need to understand who HatGuy is or what a gallimaufry entails. But the concepts are all there, and the logic is rock-solid. For baseball fans to advance, as a community, we don’t all need to know how to calculate FIP. Heck, we don’t all even have to know how to use it. What matters is recognizing the principles behind the current state of the analytical art. And I really believe FJM got it right and packaged it best.


1. The only stat that matters. The only way to pick a Cy Young winner. The thing Billy Beane can’t get in the playoffs, no matter how many fancy computers he hires to play baseball for him.

2. A simply awful pitching statistic that should be swallowed up by the earth itself, personified, given ears, and forced to listen to a tape loop of Bermanisms for all of eternity. The reason being—and again, you know this, intuitively, even if you have never quite expressed it to yourself —if Carl Pavano gives up 19 runs in five innings but the Yankees score 20 runs, and they hold on to win, and Pavano gets the win, is Pavano a good pitcher? No he is not. […] If Francisco Liriano throws nine innings of no-hit ball, but gives up a run on four consecutive errors by Terry Tiffey and gets a loss, is Francisco Liriano a bad pitcher? No he is not. Wins stink to high heaven as a way to value pitchers because they are in very large part dependent on the actions of the other guys on the team.

If someone wants to move on from there, as I did, then more power to them. But I think seeing the logic behind the above paragraphs puts someone very, very far ahead of the game, regardless of whether they want to go further down the rabbit hole. Having functional knowledge of the advanced stats is nice, but understanding why they exist in the first place is far more important.

This winter, crafting primers has been all the rage, but they’re still not where I send people curious about the wonderful relationship between numbers and baseball. Instead, I send them to the half-serious glossary of a meta-criticism blog started because its writers wanted a place to gather their thoughts. People won’t finish it knowing that wOBA is superior to OPS because of denominator problems and linear weights. But they just might leave wanting to find out more. And if not, they’ll at least have been entertained long enough to learn that:

[I]f your favorite pitcher gets off to a terrible start, but he is striking out roughly the same number of guys per nine innings that he has in the past, and he’s walking about the same number of guys he usually has, and he’s giving up homers at the same rate he usually has, but he’s allowing a BABIP of like .390, do not despair—he has gotten a little bit unlucky, probably, since the league is not going to have a .390 BA overall for the whole year. His BABIP will probably regress a little over time, and his ERA will “magically” go down.

And that’s enough for me.

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Joe R
13 years ago

I’ve always maintained that sabermetrics are almost a return to simplicity in baseball, in a perverse way.

As in, the traditional numbers have skewed people’s perception of baseball for too long. People KNOW a walk is valuable. People KNOW RBIs and Wins are highly dependent on teammates. And people KNOW if a guy makes a difficult play 9 of 10 times, and commits an error on the 10th, he’s better than the guy who never makes that play (and never commits an error). But because walks aren’t counted in batting average, so many people discredit their use when arguing between players (I’ve had someone tell me that baseball is “about hitting the ball”. Interesting, I thought baseball was about winning, which is about scoring runs, which can be accomplished by hitting, walking, getting hit by a pitch, whatever), or will use errors to analyze fielding (Vernon Wells had a .997 FP, Adrian Beltre a .959, that’s all anyone needs to know about FP).

The POINT of sabermetrics, in my mind, is to stop divorcing statistics from what actually happens in the game. To explain to people that the 2002 Oakland A’s didn’t win 103 games despite only “hitting” .261, but to explain that they won 103 games because of being 3rd in the AL in OPS+ and ERA+.

Also, I take no issue if people simply don’t care. Couldn’t tell you anyone’s stats. Ironically, some of them have a better idea of what wins a baseball game than people who worship at the altar of RBI and Batting Average. It just makes no sense to me to argue against sabermetrics and resort to “old-school” stats. It’s like they forget the actual purpose of stats, or at worst can’t figure out use for data.

Nick Steiner
13 years ago

Josh – I think you may have been missing the point of the primers out there. 

Some of the ones, yes, just explain the metric and why it’s an improvement over some other metric – and I agree that those are pretty limited in there application and enjoyableness (it’s a word – look it up). However, from what I have seen, many of the recent primers (such as the two from South Side Sox you listed) set up the problem and then offer that stats we have as a solution. 

The primer on wOBA is a perfect example of this.  He starts of by stating the goal of offensive metrics (isolation) and shows how each stat does at achieving that goal.  That shows the reader what we are trying to accomplish with the stats, and lets him make up his own mind about which one he likes.

Josh Fisher
13 years ago


You’re right about the purpose of the primers, and especially about how good those South Side Sox ones are. For people who want to learn the stats, they’re a great place to start. What I’m concerned with is that someone brand new to everything might miss the forest for the trees.


13 years ago

I think you miss a fundamental problem.

While “we’re right about baseball and we know it”, you haven’t convinced people that your way of figuring things out is valid. 

Most people simply don’t understand the basic “truths” of statistical analysis and thus treat sabermetrics as an opinion.  And you can’t prove or disprove an opinion.

Until and unless you establish the ground rules for how “being right” is agreed upon, you won’t get anywhere with a large portion of those people who have yet to adopt the sabermetric (e.g. scientific) approach.

Joe R
13 years ago

RMR is right. For example, I bet plenty of us didn’t believe OBP was better than AVG until it was pounded into our head with actual evidence why OBP was better.

Also, the argument I’ve heard is that ERA “actually happened” while FIP didn’t. So, you have to prove why FIP is better by:

1) Highlighting how FIP is a better predictor of future ERA than ERA


2) How defense / ballparks can affect ERA.

13 years ago

There is a basic problem with removing wins as a statistic… it goes against 100+ years of history. It may not be a valid stat, but it is one that is easily clung to, especially when combined with ERA. Does it make it a valid stat? No, but it won’t be removed either. It just feels wrong. QB’s also get assigned wins and nobody cares. (In my case, I didn’t even KNOW that until a few years ago) But baseball isn’t good at erasing history, in fact it embraces it. The game evolves and new stats get accepted slowly. OPS seems very popular on Sportscenter these days.

The other problem is the constant emergence it seems of yet another formula to tell me that Albert Pujols is a god. OPS does just fine, but we have that PLUS RC, RC/27, IsoP, SECA, and the dismissing of BA, like the fact that Ichiro hits .350 every year should be dismissed. Yes, SLG tells us more about what those hits were, but can’t we be amazed that he got a hit, regardless of what kind, in 35% of his at bats?

Paul Singman
13 years ago

Josh – I definitely agree with you on the FJM point; what they did to ‘debunk’ illogical stats (or rather poke fun at the people who use them) is probably the most powerful way to make people see the sabermetric side of things. Primers are nice but in terms of motivating the uninitiated, I’m not sure they come across as being as influential.

13 years ago

The reason so many people do not buy into sabremetrics,  is that the numbers and the crunching and the alphabet of stats, boils down to: 1.  baseball is an individual game, and 2. A game of luck.  We watch a game of skill played by teams.  If the math says otherwise, the math is missing something.  We don’t watch a game where everybody tries not to make outs and waits around for the 1.7 run HR.  Most of what we watch is not measured by wOBA and a lot of those things are what make the game interesting.  We talk about RBIs (not so I can prove to my friends that Andre Ethier is better than Joey Votto), because they are an interesting part of the game.

Eric H
13 years ago

Conceptually I understand that baseball is an individual game from a pitching standpoint but I’m curious if you guys have ever looked at the interaction effects of different batting orders (i.e. ‘protecting’ a good hitter with another good hitter to ensure at least one person gets good pitches). I’m sorry if you’ve already covered this but I’m new to the site.