There may be a problem, no matter which side you approach it from. Suppose the prosecution makes an offer, they're willing to go lower, but only if they think

There may be a problem, no matter which side you approach it from. Suppose the prosecution makes an offer, they're willing to go lower, but only if they think the defense will accept. The defense then rejects the offer, perhaps with the implication they might accept a lower offer. If a lower offer is made, the defense can reject it but now they have less risk—since the offer was made the prosecution is bound to x% beyond that. Some people might view that as gaming the system and I'm not sure it could be tuned to avoid that. On the other hand it might improve honesty on both sides of the table. The ratchet effect may keep the defense from being intimidated. The net effect should promote not guilty pleas among the innocent, but ideally it should not have that effect on the guilty.