&gt;Basically, if you have a DA that appears to be pushing plea bargains in cases that they can't prove in court then they will need to retry a large percentage of those cases anyway.

The problem with this is simply that most cases are highly dependent upon in the courtroom events that DA's often can't predict. Most every ADA would love to only try winners and win 100% of their cases.

The problem is that there's a chance you find out your eye witnesses is a liar during trial. Or a witness doesn't show up(even though they are subpoenaed). Or the judge makes an unexpected (or even incorrect) ruling regarding your evidence.

This system is interesting, but it places a huge burden on the prosecutors and will often end up effectively punishing them for things that are beyond their control or ability to know.