The a large percentage, perhaps even a majority, of trials end in the striking of some sort of deal before the case ever goes in front of a jury. You'd better believe that the successful local lawyer who's the DA's golfing buddy gets better deals than some zit-faced public defender who just passed the bar exam. I know that sounds quaint, but it happens all the time in America, especially in small towns where the good ole boys club is still very much a going concern.
In the UK you get 33% off the sentence if you plead guilty at the first opportunity, i.e. at the police station or the first time you appear in court, 20% at the second opportunity, etc.
