Upgrade priority infographic will improve your chances for business class on United, Delta and American

One of the biggest reason frequent fliers aim for elite status is for upgrade priority, but navigating the upgrade priority process is a messy, convoluted affair that sometimes makes absolutely no sense. That's because the airlines aren't required to publish a fully transparent process for clearing upgrades.

Sure, the airlines explain how they do it in ideal circumstances, but when it comes to flying, circumstances are rarely ideal — that's why we've gone and broken down all the essential components for upgrade priority on United, Delta and American in the graphic below. Bookmark this post so that you can play the fare game when booking your next ticket.

While Delta and United will upgrade elite fliers depending on status and fare class, American works a little differently by using a system it calls 500-mile upgrades to allow frequent fliers to self-prioritize which flights they want to upgrade. Depending on which level status elite fliers have, they are awarded a certain number of certificates, each of which is valid for up to 500 miles. So a flight that is between 501 and under 1,000 miles each way would be upgradeable with two certificates per leg.

Fare class is one of the most important factors, as it determines your priority within your elite tier. To find your fare, just look in the search results where it says what cabin the ticket is in. By understanding the way that fare classes work within elite tiers, you can work the system to improve your chances to get an upgrade.  Of course, sometimes that means rolling the dice and spending for a pricier fare class with no guarantee of upgrading. By learning the ropes, you'll increase the odds of making the right choice — and reaping the spoils of loyalty.