Team Trump grumbled about this last night, but it might — might — work in his favor on Thursday night. The Commission on Presidential Debates announced new rules last night to, er, improve the product from the first debate between Donald Trump and Joe Biden two weeks ago. Candidates’ microphones will only be live during their own answer period and in open discussion in the second and final debate. The hope is to prevent the meltdown of interruptions from both candidates, but from which Trump came off worse overall:

When the two face off on Thursday for a final televised debate, each candidate will have their microphones cut off while the other is delivering responses to questions on American families, race in America, climate change, national security and leadership.

The 90-minute debate is divided into 15-minute segments on the six topics, with each candidate granted two minutes to deliver uninterrupted remarks before proceeding to an open debate for nine minutes of each segment.

The non-partisan Commission on Presidential Debates (CPD) on Monday announced that “in order to enforce this agreed upon rule, the only candidate whose microphone will be open during these two-minute periods is the candidate who has the floor under the rules”. Both mics will be unmuted for open discussion.

The commission added in a statement: “We realize, after discussions with both campaigns, that neither campaign may be totally satisfied with the measures announced today. One may think they go too far, and one may think they do not go far enough. We are comfortable that these actions strike the right balance and that they are in the interest of the American people, for whom these debates are held.”

After initially threatening to walk away if the CPD muted mics, Trump’s campaign pledged that Trump would participate under the new rules. They had a bigger beef with the last-minute topic change from foreign policy issues, which didn’t get a lot of play in the first debate. Kristen Welker and NBC instead announced a slate of new topics, almost all of which had already come up in the first debate.

Nonetheless, Trump says he’ll press the issue himself:

The microphone moderation might end up being better news for Trump than for Biden. Although the media willfully ignored this, Biden also has a habit of interrupting in debates; he used that tactic aggressively against Paul Ryan in 2012’s VP debate, and to good effect. Biden also started the interruptions two weeks ago, although by the end Trump had clearly become the more aggressive candidate on stage with the tactic. (Chris Wallace might even have challenged Biden as runner-up by the end, too.)

In doing so, however, Trump let Biden off the ropes more than once when he got lost on policy questions. This time around, Trump’s team has already advised him to cut down the interruptions in order to let Biden hang himself:

What to watch: Trump will tell more jokes and try, if he can stay on message, to strike a softer tone. At the same time, aides expect Trump to keep going after Biden’s son Hunter.

Be smart: Trump’s team thinks that if he’d just yield the stage to Biden while the moderator is asking questions, Biden would wander rhetorically, “look doddering” and “step on himself.”

“Don’t save him,” is their advice to the president, a Trump adviser tells Axios.

It’s good advice, but it’s anyone’s guess whether Trump would have followed it. Biden had already started doing that a couple of times in the first debate; the question on taxes was critically one of those. Had Trump been more disciplined, it would have played right into his hands. Instead, Trump intervened and made the issue his lack of deportment rather than Biden’s lack of competency. Trump has a brawler’s style on stage, and lacks the discipline necessary to deploy it and restrain it tactically.

That’s why the new microphone rule might be very good news. It imposes a discipline on both men that neither really has. However, it also forces both men to respond to the policy questions rather than each other, and that’s bad news for Biden. He’s been avoiding policy discussions in order to make Trump the only issue. He got away with that in the first debate because Trump unwittingly cooperated in Biden’s strategy. This time, Biden can’t hide.