the.com/kingpin

The one person whose arrest makes the org chart fall apart.

means The central, most important person in a group or operation — remove them and the whole thing collapses.

from Straight out of bowling: the kingpin (or 'king pin') is the head pin at the front of the triangle, the one that controls how the rest fall. By the early 1900s Americans had already lifted it into slang for the most essential person in any outfit — the figure everyone else is arranged around, same as the pins on the lane.

origin
bowling term for the front pin that topples the rest
legal term
US law defines drug kingpin status for sentencing
irony
often invisible precisely because everyone else takes the risks
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