Example: When it comes to the origin of phrases, the buck stops here.
Origin: Some card games use a marker called a buck. Players take turns acting as dealer with the buck marking the current dealer. When the buck is passed to the next player, the responsibility for dealing is passed. Stopping the buck is to accept responsibility for dealing.
This phrase was popularized by president Harry Truman who kept a sign with the phrase inscribed on his desk and is a rebuttal to the older phrase "Pass the buck".
The media interpreted Harry's sign to mean he was accepting responsibility, but he may well have had something else in mind. Truman was a poker player. He knew exactly what the "buck" was -- it was the marker that identifies the person who calls the game, or in essence, sets the rules. Truman may have been saying that he was in charge and would set the rules - a bit different than just accepting responsibility.
Truman used other poker references as well - remember Truman's "New deal"?