Home-Field Advantage With No Home-Crowd Advantage

Before this post gets published, the White Sox and Orioles will begin a baseball game in Baltimore played before no one. The few scouts in attendance will keep to themselves, and those watching from elsewhere will be unheard. There will probably be birds, and birds are always making noise, but we’re generally pretty good at tuning them out, because they never shut up. Two things, before going further:

(1) Of course, what’s going on in the rest of Baltimore is of far greater significance than what’s going on inside Camden Yards. For every one thought about the baseball game, there ought to be ten million thoughts about the civil unrest, and what it means and what’s to learn. My job, though, is to write about baseball, and so this is a post about baseball. I am qualified to do very few other things.

(2) The game will be played under extraordinary circumstances, but it’s also one game. A sample of one is, for all intents and purposes, no better than a sample of zero, so we’re not going to learn much today. We’d need a few thousand of these to really research and establish some conclusions. The post basically concerns the hypothetical, inspired by what’s taking place.

Home-field advantage exists in all sports. It’s a known thing, to varying degrees. The first thing that occurs to most people, as far as an explanation is concerned, is that the team at home has people yelling in support of it. The team on the road, meanwhile, has people yelling other things at it. The average person prefers support over mean and critical remarks. Now, consider the game in Baltimore. Strip the crowd effect away completely. What could that do? What might we expect of the home-field advantage of a team that plays with no fans?

As you could guess, the answer’s unknowable. One can just try to make his best effort. To start off, this post concerns only the game of baseball, and based on the numbers, baseball has the smallest home-field advantage of all the major sports. One still exists, but it’s got nothing on, say, basketball. And, a theory: in other sports, teams might respond well to crowd noise. A boisterous environment is invigorating, and other sports are based more on momentum and effort. In baseball, you’re unlikely to pitch or hit better if you’re trying super extra hard. There could be something on the bases or in the field, but at the core of the game, it’s much more about calm and focus.

So, we’re trying to strip one element away from what’s already a relatively small effect. And while I don’t think you could say crowd has no effect on performance, home-field advantage could be a function of any number of things. Ideas people have put forward: familiarity with a ballpark, roster designed for the ballpark, advantage of hitting second, psychological benefits of sleeping at home and not traveling, umpire bias, other psychological things, and, yes, crowd noise. All these factors, and potentially others, combining to yield an overall advantage of a few percentage points.

It should be clear already that playing in front of no one probably shouldn’t make too much of a difference. It would be unquestionably weird, but those other variables would still exist. So, about the relationship between advantage and crowd noise — we don’t have a measure of crowd noise, but we do have a measure of crowd size, which is the best proxy we’ve got. And the relationship between performance and crowd size is weak. Usually, people are trying to study the opposite — the effect of a really loud crowd. Some sort of intimidating environment. There’s very little evidence that playing in front of a bigger crowd yields a larger advantage than playing in front of an ordinary crowd.

A problem there is the whole “proxy” thing — sometimes a big crowd is a quiet crowd. Sometimes a small crowd is a loud crowd. But, of significance: home-field advantage doesn’t increase at all in the playoffs. Not even slightly. You’d figure a playoff crowd would be louder and more animated than a regular-season crowd, and despite that, there’s nothing. You’re talking about 54% home wins in the season, and 54% home wins in the postseason. That strongly suggests that crowd noise just doesn’t have a real effect.

But, again, that’s talking about crowds getting bigger and louder. That doesn’t seem to matter much. But there’s a hint of an effect in the other direction. There’s nothing conclusive here, but as the linked study from THT shows, home teams before tiny crowds have been a bit less successful. The effect is observed to be equivalent to a couple wins over a season. What’s unknown is whether that’s a crowd effect, or just a sign that the would-be fans knew something the study didn’t. Maybe the fans stayed away because they thought a win to be particularly unlikely. Baseball analysis is complicated.

That concerns games played with low attendance. That doesn’t concern games played with literally no attendance. No crowd response at all. If there were absolutely no home-field advantage, you’d expect games to be split 50/50. What we see are games mostly split 54/46. It’s been suggested that by far the biggest component of home-field advantage is umpire bias. Not that they’re doing it intentionally; that they’re influenced, subconsciously, by a desire to be liked, and not booed. Makes sense. In baseball, this would show up in the called strike zone. A small crowd can still get mad at you. No one can get mad, though, if no one is present.

So then perhaps the biggest effect here would be on the psychology of the umpires. That’s a leap, something of an assumption, but maybe they’d be completely even if they didn’t have to worry about how they’d be received by a partisan audience. And as we’ve learned from pitch-framing research, an extra strike or ball here or there can make a real difference over time. So let’s try to make an estimate. Normal home-field advantage is about 54/46. No home-field advantage would be 50/50. Take all the fans away, and maybe you’d be left looking at…51/49, or 52/48. I feel like there would still be the advantages of being at home, literally, and knowing the park. Plus, there’s the whole hitting-second thing, which is a strategic and psychological inequality. But if the umpires were influenced by not being influenced, then that strips an element. I think. I’m comfortable with that guess.

You’d have a bigger effect in other sports. I’d love to know what would happen to a basketball team that didn’t play in front of anyone. A baseball team, I think, would lose one or two wins, over the course of a year. Which is important — you’re talking about eight figures of value — but you’d never be able to observe the lack of an effect in a game. It would all still feel normal. Except for, you know, that one part.