Twelfth man, sixth man, home-court advantage—whatever you want to call it, it’s nearly indisputable that a rowdy, impassioned crowd can give its team a step up on the competition.

While home crowds generally overpower those of an away team, when squads get a big fan base to travel with them, the advantage can go either way. Both sides can be just as loud, just as distracting, just as hostile, and just as crazy—causing fumbled snaps, wild penalty shots, and missed free throws.

So since we know that crowds can help to determine the outcome of a game, how can aspects of a game help to determine the crowd?

What makes spectators pull themselves out of bed for an early morning matchup, brave painfully low wind-chills for an afternoon contest, or trudge across the river for a midweek showdown?

Being a sports writer at Harvard, I’ve had the chance to watch the ebb and flow of Crimson fans throughout the seasons of several teams. While sometimes it’s easy to predict that the stands will fill up for a certain game, other times a drove of rowdy spectators appears out of the blue.

Take for instance, Harvard water polo. There are times when it seems like the only fans in attendance are players’ families or roommates that begrudgingly promised to show up. Then there are other games when the stands are filled with raucous fans, yelling so loudly that the opposing players can’t hear themselves think and your ears keep ringing even as you make your way back across the Charles.

But what about theses games creates such a big difference in the crowds?

In the case of water polo, one answer is scheduling. Schedule a game for mid-morning on a Saturday, and you basically guarantee Blodgett will be empty. But schedule that same game on a weekend evening, and you’re likely to get a host of Crimson Crazies cheering on the team before the night’s debauchery begins.

For instance, in a late September, Saturday-night matchup against Iona, Harvard had one of its biggest crowds yet, and the rowdy fans were rewarded with an epic sudden-death showdown where the trash-talking reached an all-time high (though the Crimson ultimately lost).

So in the world of water polo, timing is key.

For Harvard baseball, on the other hand, the number of fans can often be attributed to Mother Nature.

Clearly, the fact that baseball is played outside, while water polo is indoors (at least in Cambridge), means its crowds are more susceptible to the forecast. Though obvious, this effect shouldn’t be underestimated. There have been games where the sun-soaked bleachers are filled at first pitch and then desolately abandoned by the time clouds roll over and the third inning comes around.

But baseball fans also come and go for a reason that extends to all sports: the visiting team. Bigger names mean bigger crowds.

Once again, this trend seems obvious, but it shouldn’t be taken for granted, as the number of spectators at Crimson water polo games almost never vary in proportion with the skill or ranking of the other team.

This idea of opposition affecting attendance leads to perhaps the most powerful aspect through which a game can determine its crowd: rivalry.

There is nothing like pure rivalry—the combined love of competition, “your” team, and bragging rights—to motivate even the most moderate of fans. To see an example of this, we need to look no further than the event that lingers just two weeks away: The Game.

Even the most apathetic of Harvard students put down the books to join generations of alumni in the age-old battle between the Crimson and the Elis. The fact that fans actually need a ticket for The Game is evidence of the overwhelming crowds.

It doesn’t matter if The Game is scheduled at a time when some people are still waking up or if it begins to sleet halfway through; rivalry is the trump card and will ensure that the Crimson has a 12th man at Harvard Stadium.

—Staff writer Madeleine Smith can be reached at smith21@college.harvard.edu.