Sellouts in pro sports aren't always so.

Fans and media aren't shy about raising questions about attendance figures, perhaps posting a photo on Twitter of vacant seats during a "sold-out" game to support their skepticism.

Teams, meanwhile, insist they're not trying to sugarcoat a smaller-than-anticipated crowd.

Like most of the other major sports leagues, Major League Baseball tracks attendance by the number of tickets sold.

MLB also uses these figures in revenue sharing calculations, which help the game's competitive balance between large- and small-market teams. So it's about more than just a larger-looking number in the nightly box scores.

Another impact on crowd sizes is the secondary ticket market. Sometimes those empty seats have originally been sold by teams to brokers, who weren't able to resell them by game time.

By DAVE CAMPBELL, AP Sports Writer