[cm2187]

There is an interesting asymmetry between the two parties.

To the prosecutor it is just a day job, whether the guy spends 1 or 10 years in prison won't really change anything to his holiday plans. To the defendant, he is playing with his own life. He will have to be locked in a room with thugs for many years, away from his family or any prospect of a normal life.

So both parties have a very different risk aversion in that game. So the prosecution plays with that.

Now if you inflicted a significant pain (career progression, financial penalty) on the prosecutor every time he sent someone to court that turned out to be judged innocent, then you would even this "game" and would probably end up with a more fair bargain.