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.

Well, it was good for a while. The first 30 minutes showed promise. But it couldn't last ... at least for one of the presidential candidates. Today I'll base my grading of the presidential debate on strategy. Collegiate teams, in fact, win and lose debates mostly on strategy. The right strategy is essential for a debate victory, and each of the candidates came into the debate Wednesday night with a clear one. Did they pull it off?

Let's start with Hillary Clinton. Her strategy was threefold. Contrast her ideas with Donald Trump's, be presidential, and try to bait him into losing his composure (aka: let Trump be Trump).

Contrast her ideas with Trump:

This is a terrific debating tactic. I often suggest to my debaters that they take plenty of time in their speeches to go beyond highlighting our arguments and use our speech time to differentiate our positions from our opponents. Clinton did this with taxes and other issues when she talked about "my plan" and then "Donald's plan," and "let me translate that, if I can ..." My only complaint is that she should have used this tactic even more.

Strategy: A

Success: B

Photos: The final presidential debate Democratic nominee Hillary Clinton walks off stage following the presidential debate in Las Vegas on Wednesday, October 19. Hide Caption 1 of 22 Photos: The final presidential debate Republican nominee Donald Trump walks off stage with his family after the debate. Hide Caption 2 of 22 Photos: The final presidential debate Clinton gestures to the crowd immediately after the debate. There was no handshake between her and Trump. Hide Caption 3 of 22 Photos: The final presidential debate Trump speaks during the debate -- the third of three presidential debates this year. It took place 20 days before Election Day. Hide Caption 4 of 22 Photos: The final presidential debate Trump entered the debate in his weakest position yet in national polls. Recent national polls show Clinton's lead in the high single digits. And it doesn't look much better for Trump in several key battleground states. Hide Caption 5 of 22 Photos: The final presidential debate According to MJ Lee, CNN national politics reporter, Clinton's major challenge entering the debate was not so different from the challenge she's confronted over the past few months: presenting the country with a positive vision for her presidency that is detached from her argument against Trump. Hide Caption 6 of 22 Photos: The final presidential debate Clinton takes notes during the debate. Hide Caption 7 of 22 Photos: The final presidential debate "Fox News Sunday" host Chris Wallace was the moderator for the debate. Hide Caption 8 of 22 Photos: The final presidential debate Trump speaks to Clinton during the debate. Hide Caption 9 of 22 Photos: The final presidential debate Clinton is seen on a television screen at the debate venue. Hide Caption 10 of 22 Photos: The final presidential debate Trump listens to a Clinton answer. Hide Caption 11 of 22 Photos: The final presidential debate Trump takes notes. Hide Caption 12 of 22 Photos: The final presidential debate During the debate, Trump refused to say he would accept the result of next month's presidential election. "I will look at it at the time," Trump said when challenged on his claims that the election is "rigged" against him. Hide Caption 13 of 22 Photos: The final presidential debate Clinton arrives for the start of the debate. Hide Caption 14 of 22 Photos: The final presidential debate Clinton waves to the crowd before the debate. Hide Caption 15 of 22 Photos: The final presidential debate Wallace speaks to the debate attendees. Hide Caption 16 of 22 Photos: The final presidential debate Clinton's husband, former U.S. President Bill Clinton, attends the debate with their daughter, Chelsea. Hide Caption 17 of 22 Photos: The final presidential debate Trump's sons Eric and Donald Jr. wait for the debate to begin. Hide Caption 18 of 22 Photos: The final presidential debate Malik Obama, President Barack Obama's Kenyan-born half-brother, was one of Trump's guests. In July, Malik Obama voiced his support for the Republican. Hide Caption 19 of 22 Photos: The final presidential debate Bill Clinton waits for the third debate to start. Hide Caption 20 of 22 Photos: The final presidential debate Trump's daughter Ivanka attends the debate. Hide Caption 21 of 22 Photos: The final presidential debate Trump's wife, Melania, arrives for the event. Hide Caption 22 of 22

Be presidential:

This one's easy. She was steady again.

Strategy: A

Success: A

Look, a piece of cheese:

Clinton continued to bait Trump until he finally couldn't resist the cheese. I also give her kudos for patience: for the first 30 minutes, it looked like Trump might indeed not take the cheese. But Clinton stuck with her strategy, and by the end of the debate, after throwing out lines on Trump as a puppet of Putin, as a paranoid conspiracy theorist thinking the Emmy's were rigged, on his statement that he opposed the Iraq war, and on taxes, she found his soft spot.

Strategy: A

Success: A-

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Donald Trump also had three clear strategies, which were to avoid specifics on future policy, shore up the base, and truth be damned.

Avoid specific policy proposals

This was most evident at the end of the debate, when he was asked questions about future plans in Mosul and what to do in Syria or about Aleppo. Trump pivoted to talking about how we got into this mess rather than how he's going to get us out of the mess. And after all of Trump's criticism of NAFTA, the best he could muster in the debate was the generic idea that he'd somehow negotiate a "better" deal. I generally don't like this debate strategy of avoiding telling us your plans for the future; Trump simply hasn't shown that he has any specific proposals in many areas, especially foreign policy. So the best strategy for him (but not those of us who want to know) is to avoid talking about specific future policy.

Strategy: C

Success: A

Shore up the base

"Such a nasty woman." That response from Trump -- an interruption of Clinton near the end of the debate -- pretty much sums up his approach. Add to that the carping on the "rigged" election, and his assertion and that he won't necessarily accept the results of the election ("I will tell you at the time" and "I'll keep you in suspense"), and you have a candidate preaching to his choir. Trump's strategy was successful in that regard, but it's not a winning strategy for independent or undecided voters. Indeed, it's a ridiculous debating strategy. One of the first rules on our debate team is that when we have a panel of judges, we should try to debate for the judges we aren't sure about, since the ones who favor our arguments are probably going to vote for us anyway.

Strategy: F

Success: A

Truth is overrated

By now, he's been fact-checked so many times that he's simply got to know he's lying. He appears to lie uncontrollably . And yet he clearly doesn't care, since he continues to do it. In this debate, he even came up with some new whoppers -- for example that Clinton is behind the sexual assault allegations Trump has faced (there's no proof of that); that his accusers' stories about his sexual assaults are "largely debunked" (not true); that there are millions of registered voters who shouldn't be (false); that Clinton's State Department was either "missing" or had "stolen" $6 billion dollars (false). could go on , but would run out of space here.

Debates are based on the idea that we are searching for the truth. I'll say it again: You can't win a debate by lying. You won't ever get a passing grade for outright lying.

Strategy: F

Success: A+

My main point: Trump had terrible strategy. Winning over people who are already voting for you doesn't win elections, avoiding future policy doesn't help voters decide, and overt lying is, well, it's just the worst.

In fact, as Trump might put it, he had the worst strategy in the history of debates. His strategy was the biggest, the hugest disaster of all time.

We jest, but the fact remains: even with his solid first 30 minutes, Trump's mistakes in strategy are too serious to overcome. These are mistakes that prevent debaters from ever winning. Heck, they prevent anyone from passing my debate class.

Overall grades

Clinton: A-

Trump: F