You usually get one third reduction if you plead at the earliest opportunity, althogh its debateble whether this actually happens. Its a bit like car insurance, you get told you have 60% discount and when they do the insurance with the discount and you do it woithout the 60% is not what its meant to be...they work it out differently. I know you can ask for a pre trial assesment, where u can ask the judge what the sentence would likely to be if found guilty on trial and what it would be roughly if trial was not to go ahead, i forget what this hearing is called, but i know u can ask for it. The trial judge has read all the papers beforehand and he knows exactly what he will give if the verdict is a guilty one. Regardless of pre sentence reports etc...they are just formalities to please the home office and stat ppl.