Wins Above Replacement isn’t a household statistic, and it never will be. It’s too complicated, too theoretical, too unnecessary for most baseball fans. With that said, today more people know about WAR than ever, with the metric routinely coming up on websites and on television. It is, rather understandably, controversial, and plenty of people out there dismiss it without a second thought. While it’s been around for years, I think what really launched WAR to the greater public was the first go-round of the Mike Trout vs. Miguel Cabrera MVP debate. That’s when WAR started getting a lot of play at places like ESPN, and more people were introduced to the framework and to some of its declarations.

Most of the ways WAR gets used are for comparative purposes. People love to see rankings, and people love to know which players are better than others. It also gets used in contract analysis, especially around these parts, and it’s hard to remember how we used to write those posts before we had the numbers we have today. With WAR, it’s really easy to get wrapped up in the details, because the metric allows for such detailed interpretation. But the one most important thing I’ve personally learned from WAR is probably the most general of its points. That is, WAR has provided me with an idea of what baseball players are worth to a team.

Take a player. Take any player who’s a regular, and go to one of his team’s message boards and write a little thing about his WAR. Some people are going to disagree with it. Some people are going to ignore you. But others, still, will engage you and tell you why the player is better or worse. Plenty of people disagree with individual WAR ratings, and that’s OK, because WAR is imperfect, for a variety of reasons. At least, the inputs are imperfect. The framework’s just fine. But anyway, while people don’t always see eye-to-eye on the individuals, I haven’t seen many people bicker with the idea that an average player is worth about two or three wins. It’s accepted that a good player is worth about three to five wins. It’s accepted that a star player is worth more than five wins. And the truly elite can get up around eight or 10. WAR, clearly, also is controversial. In general, people seem to accept its scales. Most of the fights are over decimal points.

For the longest time, that’s something I never had any concept of. I understood some players were better than others; I understood some players were fractional approximations of superior players. Getting actual values, though, changed almost everything. The absolute best player in baseball is worth about 10 wins over a 162-game season — relative to some ordinary Triple-A type. A good player could be worth a third of that. I’m floored by the number of ways in which this has informed my thinking.

The reality is that any given player means relatively little. Maybe that ought to be obvious: A team has several regular position players, and several regular starters, and an entire bullpen full of guys. Baseball, certainly, is a considerable team effort. But if you consider the goal, say, making the playoffs, a given player makes a difference of only some percentage points. Even big splashes can look kind of like small splashes. Small splashes can be virtually inconsequential splashes.

If a talented player has to go on the disabled list, obviously it’s more bad than good, but it can almost never be crippling. If the player’s only gone for 15 or 20 days, the damage might be almost entirely negligible. A 15-day DL stint represents one-twelfth of the regular season. Good players are worth a handful of wins over a full regular season. I doubt I need to lay this out.

I know I used to stress out about midseason moves, if I was following a contender, which has happened. Fans really don’t appreciate it when their teams allow the trade deadline to fly by without significant improvements being made. By definition, an improvement is an improvement and improvements boost odds, but by the middle of the year you’re looking at half a season left, and by the deadline you’ve got two months. It’s a narrow window for a player to make a difference, and such a limited impact can be worth only so many resources going in the other direction.

And there’s something to be said about organizational success windows. People think the Kansas City Royals have to contend this season, before they lose James Shields. People think the Seattle Mariners have to contend before Robinson Cano begins his decline. People think the Baltimore Orioles have to contend before they face difficult questions about some of their own stars. Windows do exist, to some degree. To use the Royals as an example: They’re closer to contention with Shields than they are without him; but even without him, they’re left with a similar team, just without one starting pitcher. If the Royals don’t make the playoffs in 2014, they don’t have to tear everything down because Shields became a free agent. They could try to build a contender again for 2015, and it would be far from impossible. A decent team with a good player is a mostly decent team even without him.

Writing this out, I’m left wondering whether it’s even been worth writing this out. It all sounds so simple and obvious to me, and that isn’t what FanGraphs is supposed to be about, except for when the next team signs Yuniesky Betancourt. We’ve accepted the point of WAR for years. But take a moment to appreciate how that’s had an effect on you and on your own fandom. I’m a completely different baseball fan than I used to be. The emotion can still be there for the games, but in between, I’m a lot more mild-mannered. I worry less about individual players, because individual players are cogs in a giant machine. Groups of moves can make a big difference, but particular moves often just make the needle wiggle a little bit. Seasons aren’t won and lost on singular transactions.

That is, unless we’re completely and hopelessly wrong about clubhouse chemistry and those sorts of intangibles. I don’t know — that’s a separate frontier, and I’m not among the explorers. Maybe players make an enormous difference after all. I’ll await the evidence.

I can see the way WAR has had an effect on my following hockey. I’m not so concerned about offensive defensemen being mediocre in their own end; and I’m not so concerned about defensive forwards being mediocre in the offensive zone. It has to be all about overall value, with all of the attendant pluses and minuses. That’s an example of a way in which WAR has crossed a boundary.

In baseball, though, as much as I like to use WAR for comparisons and evaluations, the most important thing it’s taught me is simply what average and good players are worth. And mediocre players, and great players, and all the players in between. It feels like a fairly fundamental lesson, but you’ll never get anywhere without the fundamentals.