A little-known definition of buck is a counter or marker passed from one poker player to another to indicate an obligation, especially one’s turn to deal. It’s also known as a button or dealer button. This is the sense of buck meant in the idioms pass the buck and the buck stops.
Pass the buck
To pass the buck is to hand a task or responsibility to someone else. It often has pejorative connotations in reference to the person passing the buck. These writers use pass the buck well:
Perhaps that is because the name of the game is to pass the buck to Congress to do the hard work of digging out of the fiscal mess we are in. [Washington Post]
That ridiculous remark tells you all you need to know about Mr. Christie’s responsibility-shirking, pass-the-buck approach, not to mention his grasp of history. [New York Times]
They are now trying to pass the buck when it is entirely their fault in the first place. [Daily Mail]
The buck stops
When the buck stops with someone, that person accepts responsibility and doesn’t pass it on to anyone else. Unlike pass the buck, which is usually pejorative, being the person with whom the buck stops is something to be proud of. For example, U.S. President Eisenhower famously kept a sign on his desk that said “The Buck Stops Here.” Of course, being unwilling or unable to rise to the occasion and accept the buck is shameful.
Here are a few examples:
Some critics say the buck stops with the president, so Obama must lead the way on this issue. [Creative Loafing Tampa]
His response, to decapitate a troubled department, turns on the popular idea that the buck stops at the top. [Valley Advocate]
And when police break the law, the buck stops at the top, not the bottom. [Washington Examiner]

