Each autumn, Katmai National Park in Alaska celebrates ursine obesity in the best way possible: by holding a week-long competition to determine which bear is the fattest.

Since park rangers can’t exactly ask a wild brown bear to stand on a scale, it’s less about how much the bears might weigh and more about how much larger they’ve gotten since the spring. According to explore.org, which hosts the online event, the bears will drop about one-third of their body weight while hibernating over the long winter. In order to survive those months without any food or water, they spend the summer scarfing down all the salmon (and other sustenance) they can get their paws on. By early October, they’re gloriously corpulent—and it’s up to you to decide which one deserves to be the champion of this year’s Fat Bear Week.

Every day between now and October 6, Katmai National Park will post one or two new bear-vs.-bear matchups—the first at 12 p.m. EDT and the second at 4 p.m. EDT—and ask the public to vote for the bear they want to see advance to the next round of the single-elimination tournament. Each entry includes a photo of the bear from June or July and another from the last few weeks, so you can easily see how much they’ve ballooned.

You can learn about the bears on the “Meet the Bears of Fat Bear Week” page, and you can also try to spot them for yourself on explore.org’s livestreams. Once you’ve chosen your favorite, you can see which competitor they might face next on the bracket. Last year’s winner, Holly, is defending her title, but she might have a conflict of interest—this year, her cub is competing, too. If Holly wins her next round, and her cub wins her next two rounds, mother and daughter could battle it out in the semifinals on Monday, October 5.