Here's one that walks through the process:
https://www.popehat.com/2013/03/26/cloudy-with-a-chance-of-s...
Here's another, more hyperbolic one, showing how a claimed "facing 67 years" turns out to be more like "facing 24 months, and probably less than that":
https://www.popehat.com/2013/02/05/crime-whale-sushi-sentenc...
But the short version is that describing a criminal case as "facing up to 50 years" is like describing a lottery ticket as "worth up to 50 million dollars", and you should probably believe both statements about equally until the sentencing happens (for the criminal case) or the winning numbers are drawn (for the lottery ticket).