Todd Graham is the director of debate at Southern Illinois University. His teams have won five national championships and advanced to the "final-four" of a national championship tournament nine consecutive years. He's been recognized three times as the national debate coach of the year. The opinions expressed in this commentary are his.

(CNN) On Monday night we witnessed the most hyped and highly anticipated American presidential debate in history. And it didn't disappoint in demonstrating the stark contrasts between the candidates.

The pre-debate rundown was that Hillary Clinton might be deeper on substance and logic, but Donald Trump should best her on personality and humor. Therefore, those are my grading categories.

Substance/logic

Clinton: A-

She didn't have many stumbles. She left a few things unanswered, such as Trump's claims that she was nasty toward President Barack Obama when she was running against him in 2008. But overall Trump left her substance mostly unchallenged.

For example, Clinton had the best rationale I've heard for why Trump won't release his tax returns. She "four-pointed" (to use a debate term) Trump.

1. Maybe he's not as rich as he says.

2. Maybe he's not as charitable as he says.

3. Maybe he owes a lot of money to banks.

4. Maybe he paid no federal income taxes (for troops, vets and schools, she helpfully pointed out).

Trump had no answer in the debate other than perhaps to reveal a "tell": When Clinton mentioned "the only years (of tax returns) that anybody's ever seen were a couple of years when he had to turn them over to state authorities when he was trying to get a casino license, and they showed he didn't pay any federal income tax " -- a questionable assertion, say the fact-checkers -- he interrupted her only to say "that makes me smart."

JUST WATCHED Trump: I'm 'smart' for paying no taxes Replay More Videos ... MUST WATCH Trump: I'm 'smart' for paying no taxes 00:51

I also liked the subtlety of some of Clinton's debate tactics. She knew Trump would argue that the Iraq War was a bad idea, and that he would blame the US withdrawal from Iraq for the rise of ISIS. So she answered this by reminding the audience that it was George W. Bush who set the timetable of the Status of Forces Agreement that would remove US troops by 2011, and that Obama couldn't renegotiate it to leave a residual force in Iraq without the approval of Iraq. And Iraq did not approve.

Trump missed this argument.

Clinton also knew Trump would rail about the Iran nuclear deal. So she asserted that before a sanctions regime she helped usher in, Iran was weeks away from developing a nuclear weapon -- which is, to say the least, a debatable sequence of events . But Trump missed this argument, too.

And on trade deals, after a rambling speech from Trump, Clinton pointed out that "trade is not our only challenge" for the economy. Yet again, Trump failed to respond to this point.

Trump: F

Where to begin?

In debate jargon, Trump had "claims without warrants." He offered no proof for many of his arguments and conclusions. He did this tons of times. Asserting the Fed is political and only helping the economy to make Obama look good, asserting that "stop and frisk" was why crime went down, saying that ISIS was beating us at our own game when referring to cyberwar. Just three examples of claims without warrants.

An important trait for a debater is to be "topical." In other words, debaters should address the question being asked. And I'll be honest, I tried to follow Trump's train of thought. I really did. But once a train is derailed, it's pretty tough to see all the cars.

JUST WATCHED Donald Trump defends tax cuts for the wealthy Replay More Videos ... MUST WATCH Donald Trump defends tax cuts for the wealthy 02:14

Organizationally, he just rambled. Debate judges call this a "messy" debate. Heck, one question was about taxes and somehow Trump ended up talking about our airports being like Third World countries. Finally, at times he made little sense, using the words "nuclear" and "cyber" as if they were complete sentences.

Trump's worst moments mirrored his worst moments at his first debate of the Republican primaries. He simply appeared both racist and sexist. There's no nice way to put it, well, because it's not nice. Not at all.

Racist

When Clinton hammered him on the birther movement , his answer, instead of an apology, was to repeat that in demanding a birth certificate from the President he did a good thing and that Obama should have produced it a long time before (as if challenging our first African-American President's birthplace was somehow anything less than racist).

And, shockingly, Trump actually made a new, even more racist argument. He actually said that "the African-American community ... really wanted me to come to that conclusion and I think I did a great job and a great service, not only for the country but even for the President in getting him to produce his birth certificate."

Was there even more racism? Why yes, thank you for asking.

JUST WATCHED 5 times Donald Trump was live fact-checked Replay More Videos ... MUST WATCH 5 times Donald Trump was live fact-checked 02:37

Perhaps you missed Trump patting himself on the back for, essentially, not being sued for discrimination in Palm Beach when he opened a club. Congratulations, you followed state and federal discrimination laws this time. And he reminded us that though he was the target of racial discrimination lawsuits by the Justice Department, they were "settled" with no admission of guilt. Yes, that's what people usually do when they "settle." But that hardly equates with innocence.

Trump also avowed his support for stop-and-frisk policing but then lied in front of the audience about whether or not a judge had properly found it to be illegal. The practice was in fact found to be unconstitutional, specifically on the grounds that it was racist and discriminatory.

Sexist

After Clinton hit him with his previous statements about women, Trump once again didn't apologize, but instead referenced an attack at Clinton that he could have made in retaliation for her bringing up the sexism issue, but didn't because he's not that kind of guy. He repeated insults he'd aimed at actress Rosie O'Donnell, just like in the first Republican primary debate. So in other words, when accused of being sexist, Trump actually said the phrase, "She deserves it."

More sexist? Sure, why not. Oh, and let's throw in some more racism to boot. At one point, Clinton quoted Trump calling a Latina Miss Universe "Miss Housekeeping." Clinton then smartly stated, "Her name is Alicia Machado. She's a United States citizen, and she's going to vote this November."

Personality/humor/nonverbal

Clinton: B-

Clinton won the this battle, that's for sure. But not because she was awesome. While her steady-as-she-goes approach was successful on the nonverbal front, it probably brought down her vocal inflection, where I'd like more variety. She's still a bit stiff.

And I understand she wants to contrast her style with Trump's, but still, c'mon. If somebody interrupted you like Trump did her, you'd never tolerate it. I coach my debaters to call out the other person. So just once, at least once, I'd like Clinton to have said, "Mr. Trump: Stop. Interrupting. Me."

JUST WATCHED Clinton: Trump called women pigs, slobs and dogs Replay More Videos ... MUST WATCH Clinton: Trump called women pigs, slobs and dogs 01:56

The stamina question. Well, it wasn't a stamina question Lester Holt posed, but as Clinton pointed out, it was a question to Trump about his comment on her "looks" that in midanswer Trump switched to an issue of "stamina." I'm putting this under personality since Trump's made such a big deal about stamina the entire campaign.

Clinton had maybe her best answer of the night here, reminding us of the real topic (looks/sexism) and then moving to her experience of being in 112 countries, negotiating ceasefires and testifying before Congress for 11 hours. Once he's done this, she quipped, "He can talk to me about stamina."

Trump: F-

For nonverbal communication, Trump was awful. While Clinton was speaking, Trump scowled, frowned, gave the evil eye, sniffed and sighed. And this was on the very first question. After that, it was 90 minutes of "let's interrupt the woman on the stage." It was rude and annoying, and in this case it only added to the impression that Trump was sexist.

I've seen this too many times in debates, and the impression is lasting. Finally, there were only two of them on stage, and he still was compelled to interrupt and say "wrong ... wrong ... wrong" during her answers. He didn't care that he'd get his turn. Trump simply couldn't stand being criticized.

Overall grades?

Clinton: B

Trump: F