How does the rankings work?

[Quiksilva]

Say for example, Parker lost his WBO heavyweight title to Joshua on Saturday night, how does a boxer who lose their title climb their way back into the rankings for a title shot/mandatory position?

[BLASTER1]

Say for example, Parker lost his WBO heavyweight title to Joshua on Saturday night, how does a boxer who lose their title climb their way back into the rankings for a title shot/mandatory position?

By fighting and beating the opponents that are higher up the rankings that you are.
Not rocket science.

[Clegg]

Aside from beating the guys above you, one way is to fight for a regional title. If you win the IBF Intercontinental title you get bumped higher up the rankings. Most of the discussion is done behind closed doors and not based upon a perfect formula and even though they say the bribery culture was rooted out a few decades ago it likely still goes on just on a smaller scale/less often.

[Kezzer]

The BoxRec is calculated based on statistics. For example, Joshua has taken on much tougher opponents (with better resume etc) than Wilder so has a far higher points score. The tougher the opponent the more points scored for a win; the type of win als is factored in.

The governing bodies, well - what can you say! In theory you beat those ranked above you but all of them have quirks and place random guys in the top 15 etc.

As an example WBC have placed Bellew rank7 after his win over injured Haye. BoxRec in my opinion is the closest to an unbiased view and fairer overall picture.