This chapter begins by explaining the contradictory expectations of trial judges in criminal cases in the United States. On the one hand, the system is deeply distrustful of trial judges—they are to be “neutral referees” at trial. Juries, not judges, must determine guilt even for very minor crimes. But when it comes to sentencing, trial judges have been vested with nearly unlimited power over the length of a defendant’s sentence. The U.S. tradition is that there is no appellate review of a sentence as long as the sentence falls somewhere within the broad sentencing range for the crime. The chapter explains how our sentencing tradition came under sharp attack in the 1970s. To try to bring greater consistency and fairness to sentencing, states—later followed by the federal government—began to develop sentencing guidelines systems. The chapter explains the problems that quickly emerged with the federal sentencing guidelines system which were detested by judges, had the effect of shifting sentencing power to prosecutors, and increased the severity of sentences. The failure of the federal sentencing guidelines system was unfortunate as sentencing reform is much needed and the sentencing guidelines model is sound if implemented in a balanced way. State guidelines systems have been much more successful at bringing consistency and fairness to sentencing while also reducing the severity of sentences.