Editor's note: Todd Graham is the director of debate at Southern Illinois University. His teams have won five national championships; he's been named the national debate coach of the year three times and been presented with the lifetime achievement award in academia and debate. You can find him at his website, Facebook and Twitter. The views expressed in this commentary belong solely to the author.

With a mute button at the ready -- and a no-nonsense moderator in NBC's Kristen Welker guiding the proceedings in Nashville -- America got a better presidential debate Thursday night.

I coach debate teams for a living, and I'm going to dive into the categories where most debaters make their living: Substance, logic and strategy. I'll evaluate President Donald Trump and former Vice President Joe Biden one at a time on those two criteria, finishing with their final grade.

JOE BIDEN

Substance and Logic

B
The coronavirus was the first topic, and Biden was outstanding in his presentation —describing his plans for the future, encouraging more mask wearing, outlining national standards to open schools and businesses and describing greater availability of rapid testing -- and in his criticisms of the Trump administration's record thus far (more than 220,000 dead, with daily death totals surpassing 1,000, and spikes in many states).

Biden's answers to Welker's questions on several topics were on point. On race, Welker asked if Biden understood "the talk" that people of colour give to their children to prepare them, she said, "for the chance that they could be targeted, including by the police for no reason other than the color of their skin."

Biden explained in detail his grasp of the issue and noted that his daughter is a social worker who has written on the subject.

On climate change, Biden flatly stated that it was an "existential threat to humanity," and noted scientists' warning that "we don't have much time," but then took it a step further and explained that acting now could boost the economy while protecting the environment.

Biden's substance wasn't perfect. He didn't effectively tie the other topics of national security, the economic plight of American families or race and leadership to the Trump administration's failures on or his own plans to combat the coronavirus, which would have been easy transitions to make .

Strategy

C-

Simple word choices and turns of phrases make a difference in debates. "I'm going to shut down the virus, not the country" was smart. Biden also cleverly used Trump's language against him on the topic of coronavirus after Trump said we are, "learning to live with it." Biden spun that around: "He says that we're learning to live with it. People are learning to die with it."

Biden's weakness was that he got pulled onto Trump's ground too often in the "open discussion" section of the debate. A perfect example of this was when Trump got Biden to answer his question, "Would he close down the oil industry?" Biden took the bait, "We need other industries to transition" away from the oil industry, "to get to zero emissions."

While Biden may have meant for this fuel transition to be over a long period of time, he wasn't specific enough. So naturally, Trump framed it as "a big statement" and made Biden appear radical. "Will you remember that, Texas, Pennsylvania, Oklahoma?," Trump said.

Biden failed in other exchanges with Trump in the back half of the debate. He wasn't clear or decisive when Trump painted him as an insider who never accomplished much. Biden should have responded much more strongly and said that his efforts were often blocked by Republicans in Congress and that some of Trump's policy victories were actually Democratic proposals.

Finally, Biden spoke with too much sarcasm and irony, which rarely play well during debates. His excessive use of the phrase "Come on" became tiresome.

Overall grade for Biden:

C+

DONALD TRUMP

Substance and Logic

F

Trump's answers to Welker's questions were atrocious. Remember: The topics were announced in advance, and Trump still couldn't manage a single direct answer. This is a capital debate offence. Please read on. It's important.

On coronavirus: "How would you lead the country during this next stage?" Trump had no plan other than hope for a vaccine, an expressed wish not unique to him, his administration or even our country.

On national security and foreign interference in U.S. elections: "What would you do in your next term to put an end to this threat?" Trump rambled on about Russia, horrible emails, and some random news conference that he tried to use to vaguely accuse Biden of ...something...it was hard to understand.

On American families and his administration fighting to overturn the Affordable Care Act, "What would you do if ... people have their health insurance taken away?" Trump's reply? He'll "terminate Obamacare, come up with a brand new, beautiful health care" plan, but was unclear, even after being the President for four years, on when it would happen or how it would work.

On the question about race in America to which I alluded earlier, Trump said yes when asked, "Do you understand why these parents fear for their children?" But he moved quite unsympathetically away from the people who were the topic of the question into attacking Biden's support for a crime bill 26 years ago.

On climate change Trump was asked how he would "combat climate change and support job growth at the same time." While he mentioned his trillion trees program in passing, he avoided even saying the words "climate change," completely.

Finally, on the topic of leadership, consider this question: "Imagine this is your inauguration day. What will you say in your address to Americans who did not vote for you?" Trump's response was: something ... plague from China ... something ... MIT graduates ... something else, and 401ks going to hell. I don't intend to be glib; that's how incoherent, wasted an answer it was.

The other capital offence was a violation of the cardinal debate rule: Don't lie. Trump's dishonesty was on full, unrelenting display — ask the fact checkers. Any audience -- in this case, the American people -- should never become numb to lying in debate. Never.

But Trump's substance wasn't all bad. I actually thought he gave good examples during the portion of the debate covering race. His criticism of the 1994 crime bill Biden worked to pass, Trump's new funding to historically Black colleges universities and his efforts at criminal justice reform were all excellent points to raise. Unfortunately, Trump's wash of hyperbole too often detracts from his credibility on many issues and Thursday night was no exception. Comparing himself to Abe Lincoln? That dog don't hunt.

Strategy

C

The nicer version of Trump always seems to win over people who think this time, just maybe, he's finally turned the corner on civility. Given how much independent voters disliked Trump's showing in the previous debate, civility was the right strategy Thursday night. Unfortunately, Trump's greatest strength was also his weakness. The focus of the debate now became the content of his answers. That's where the Emperor had no clothes, with Trump's policy proposals largely (in)visible for everyone to see.

Overall grade for Trump:

F

His good moments can't make up for breaking the cardinal sins of debate: not answering the questions and displaying pervasive dishonesty.