WHICH sport is the world's favourite? The answer, football, feels so self-evident that it is barely worth a post. But what about the world's second favourite?

In 2005 England was in the thrall of a glorious cricketing summer. That year's Ashes series, a biennial battle in which Australia used to thrash England (before gloating about it insufferably), was going to the wire. Five wonderfully close Test matches had brought the country to a standstill. (It even knocked The World's Favourite Sport off of the back pages for a while.)

Out of curiosity, I checked out the American press to see whether news of this parochial clash obsessing England had made it across the pond. It was with pride that I saw that it had made the New York Times (if I remember correctly), albeit in a report so hidden away that it seemed surprised to be found. The article stated—casually, with no supporting evidence—that cricket was the “world's second most popular sport”. The next day I saw the claim again, equally unsubstantiated, in the British version of the Times.

I was reminded of this recently by a comment on our inaugural Game Theory post: “After soccer/football, what is the world's SECOND most popular sport?...I heard it may be cricket, but controversy abounds.” It got me wondering how one defines a sport's popularity.

The first definition that leaps to mind is the number of people watching it on television. But does one measure a single sporting event, or the number of people who watch a game over the year?

The only time a billion people have watched a single sporting-related event was the opening ceremony at the Beijing Olympics in 2008, according to futures sport+entertainment, a consultancy. In fact it is the most-watched TV programme of all time. Still, I don't think a cutesy Chinese kid lip-synching a sickly song about how the world is one happy family really counts as sport.

Kevin Alavy, the director of futures sport+entertainment, says that “broadly speaking, the FIFA World Cup and the Summer Olympics are by far the two most-watched sporting events, with the UEFA European Championships ranked third. There's then quite a large gap to…the FIA Formula One World Championship, NFL Super Bowl and the IOC Winter Olympics.”

So where does cricket fit in? By these figures it seems preposterous to advance it as the world's second favourite. However, the number of people watching its showpiece, the World Cup Final, is wholly dependent on whether India has made it through. It would be of little surprise to me if, in a non-Olympic or World Cup summer, this year's final between India and Sri Lanka—in Mumbai—was the most-watched sporting event in 2011.

Yet I don't think these one-offs are a good indicator. In 2008, the second-most watched sporting event (not featuring cutesy kids and the like) was a volleyball game between China and Cuba. I've accidentally sat through a baseball game on television. But I'm not a fan and I don't want my name chalked up alongside it when awards for popularity are handed out.

Which leaves us with the notion of “regular” viewers. Here, cricket might be a viable contender for second. What is important is not that it is a global sport—very few countries give a hoot about it—but that it is phenomenally popular in two places, India and Pakistan, whose combined population makes up over a fifth of the world's total. In contrast, American football attracts little attention outside the United States, which has just a quarter of India's population.

Supporting from the stands

How about attendance figures? By this measure Major League Baseball (MLB) storms it. In 2010 combined attendance was over 73m, although it has the advantage of a stupendous number of games in a season—2,424. The second-most attended sporting league in the world is also in baseball—Japan's Nippon Professional Baseball, with over 22m spectators in 2009. In contrast, the English Premier League attracts just 13.2m to its stadia. Indeed, football's six most attended leagues—England's Premier League (EPL), Germany's Bundesliga, Spain's La Liga, England's Championship, Italy's Serie A and French Ligue 1—muster fewer specatators between them, with 64m, than MLB alone. Then again, most have a mere 300-400 games in a season, meaning that the average attendance per game is comparable (30,138 for MLB and 34,780 for the EPL, for example). The best average attendances are at NFL games (66,960) followed by the Bundesliga (42,673).

We might also consider revenue. According to Deloitte, the EPL's revenue in the 2009-10 season was €2.3 billion ($3.1 billion), with football in the whole of Europe generating a combined €16.3 billion. This compares with NFL's $9 billion, MLB's $7.2 billion and the NBA's $4.1 billion in 2011, according to Plunkett Research. Comparable revenue figures for the Indian Premier League, cricket's big money-spinning event, are hard to come by. But Brand Finance, a British consultancy, estimated the IPL's brand value to be $4.1 billion in 2010.

Are there other measures we can use? The number of Google hits is a tempting proxy. However, this is problematic for two reasons. First, it will favour sports that are popular in countries with high internet penetration. Even if one could adjust for that, however, there is still the issue of the word “football”, which encompasses both the world game and gridiron. If you type “football” into Google, you get 1.5 billion returns. “Soccer”, which relatively few people outside America use, gets 740m, while “American football”, used exclusively outside the United States, notches 36m. So it is likely the big majority of those 1.5 billion refer to the roundball game. “Basketball” gets you 627m hits, “cricket” 351m (although some of these might be of the six-legged variety); “golf” 271m; “volleyball” 177m and “Formula 1” 90m.

An alternative test would be how many people can recognise a star player. This would give the individual sports a boost, since stars like Roger Federer and Michael Schumacher have their faces adorned on billboards around the world—although I also refuse to believe there is a single person on the subcontinent who would be unable to put a name to a picture of Sachin Tendulkar (27m Google hits, pictured above). And there are probably undiscovered Amazonian tribes that could finger David Beckham (67m).

Still, what share of people who could name Tiger Woods are really golf fanatics? So my proposed test is as follows: can you fully explain the most arcane rule in the sport you purport to follow—lbw in cricket, offside in football or what is happening virtually any time the ref blows his whistle in rugby? This would surely sort the true fans. Now we just need to find someone to pay for the survey.

UPDATE: Many of the comments have asked why we haven't included participation rates in the post. It was an obvious oversight, so I have had a dig around for some stats. Unfortunately, I don't think they add much clarification. The National Sporting Goods Association publishes a list for the United States. But it ranks walking, a sport apparently enjoyed by 95.8% of Americans over seven years of age, at number one. The first real sport we come to is swimming, in which just over half of Americans participate. In Britain, depending on your source, the most popular sports by participation are either swimming or angling.

But clearly, not everyone who happens to take a dip is partaking in the sport of swimming. I would argue we should only include organised participation. So only people who play for a Sunday league football side, not those who play in the park with jumpers for goalposts; people who run a race, not every jogger. Compiling that list, I suspect, would be a full-time project.