People who get "traded" for in history...

[naraht]

In a good number of timelines, if a person who died in OTL lives, then someone who lives in OTL *must* die or vice versa.

The examples that I've seen more than once include
JFK lives: either Jackie or Gov Connally dies
Lincoln lives: his wife dies.
Freddy Mercury lives (never gets AIDS): Elton John dies of AIDS
FDR dies: Chicago mayor Cermak lives


Any others spring to mind?