Texas A&M has a 1-in-5 chance of beating Bama. Here are the 5 keys to an upset.

Maybe the only thing crankier than Alabama head coach Nick Saban’s response to a loss is his response to a win. And after 19 wins in a row, with a huge game against No. 6 Texas A&M on deck (3:30 p.m. ET, CBS), he’s as antsy as ever. He’s yelling at his defensive backs. He’s stressing about blocking Texas A&M’s awesome pass rushers. He’s chewing his running back’s ass about taunting an opposing fan.

Saban is dialed in, as is his team. His offense is helmed by a true freshman quarterback but is averaging 45 points per game all the same. His defense allowed 43 points to Ole Miss a month ago and has allowed only 46 since. (Including special teams, Bama defenders have also scored 11 touchdowns this year.)

Saban’s Crimson Tide survived a brutal early test at Ole Miss. In-game stats only gave them about a 39 percent chance of winning, but they got by thanks in part to three return touchdowns. And since then, they have been untouchable. Beating Kent State and Kentucky by a combined 82-6 was to be expected. Beating Arkansas and Tennessee on the road by a combined 98-40 was not. Those were supposed to be tests.

Saban called Alabama’s 49-10 win over Tennessee his team’s “most complete game.” Any time the Tide play that well — they outgained the Vols by 431 yards and produced a 74 percent rushing success rate to UT’s 21 percent — they will probably win, no matter the opponent.

But you don’t play your best every week. And if Alabama gives A&M an opening, Kevin Sumlin’s Aggies might be strong enough to take advantage.

A&M ranks higher in S&P+ now than it did heading into last year’s game, but only barely. The Aggies were 15th when Bama came to town — ninth on offense and 48th on defense. This year’s squad is more balanced (17th on offense, 25th on defense), but the Crimson Tide are given a 79 percent chance of winning all the same.

That leaves 21 percent for the Aggies, though. How might a 1-in-5 upset bid play out on Saturday? What happens in that one game?

1. A&M finds a way to take advantage of Alabama’s newly risky defense.

Alabama opponents have thrown 232 passes; Bama defenders have gotten hands on 37 of them, and 35 of them have been thrown by a quarterback under duress. (On 27 other occasions, Bama has brought the QB down before he could even throw.)

Part of the Crimson Tide’s evolution has been ramping up the aggressiveness. Previous Saban defenses would flow to the ball and gang tackle, and that’s still part of the equation. But in an effort to turn the tables on the kind of up-tempo offense that would occasionally mean trouble, Bama takes the game to the opponent.

Bama’s defense ranked 103rd in Adj. Sack Rate in 2013, 92nd in 2014 ... and second in 2015. The Tide are 10th this year. In 2015, 65 teams finished with fewer than 27 sacks, and Bama has that many in seven games.

Pressure leads to stress, which leads to mistakes, which leads to Alabama defensive touchdowns.

It also leads to big gains by opposing offenses, though. IsoPPP measures the magnitude of a team’s successful plays; using success rate and IsoPPP, you can break offense into two questions. How frequently are you successful? And when you’re successful, how successful are you? Risky defense frequently pays off because of the turnovers and three-and-outs.

But it can still lead to you getting burned, and Alabama ranks 121st in Def. IsoPPP.

Alabama’s defense ranks 10th in FBS with only 70 gains of 10-plus yards allowed, but the Tide rank 58th in gains of 20-plus and 65th in gains of 40-plus.

Texas A&M’s offense: ninth in IsoPPP and third in gains of 40-plus yards.

If Alabama’s aggressiveness results in a couple big-gainers by running back Trayveon Williams or a couple of bombs to Josh Reynolds (19.5 yards per catch), Ricky Seals-Jones (17.5), or Speedy Noil (14.5), A&M can keep up.

Saban told media this week, “The field is spread quite a bit when you play them. If everybody doesn’t fit (the gaps) exactly right, there’s a lot of air between (Williams) and the next defender, and he certainly knows how to take advantage of it.”

2. Efficiency, somehow, some way.

The odds of big gains for A&M will directly correlate to down and distance. If Trevor Knight is throwing passes on second-and-5 or third-and-3, Bama’s pass rushers won’t be able to pin their ears back, because of the threat of the run.

The problem: It is nearly impossible to remain efficient against Alabama. Only teams with extremely efficient offenses beat Alabama.

Of Bama's 12 losses since 2008, six came to teams ranked in the Success Rate+ top five and 10 came to teams in the top 20. If you're able to effectively move the ball four to six yards at a time and avoid passing downs, only then can you utilize the tempo and spread principles we've seen Alabama struggle with from time to time. Plenty of spread offenses have failed miserably against the Tide.

So, in more than seven seasons and 101 games, Alabama has lost just three times to a team ranked worse than 13th in this category.

I wrote that in mid-Oct. 2015. Alabama has still only lost 12 times since 2008.

Heading into last year’s game, A&M ranked 49th in Success Rate+, and the Tide rendered the Aggies woefully inefficient.

This year, despite all the big-play potential and Williams’ emergence as a big-play back, A&M ranks 47th in Success Rate+. Uh oh.

3. The Aggies create second-and-longs.

One of A&M’s biggest advantages is being fantastic at stuffing runs at or behind the line; Alabama is only decent at avoiding it. A&M’s defense ranks fifth in stuff rate, and Bama’s offense ranks 51st.

The Aggies are also one of the better teams in the country at generating pass pressure even on standard downs. And starting Alabama lineman Alphonse Taylor is still working his way back from a concussion.

Saban expressed concern about scheming to stop the dynamic duo of linemen Myles Garrett and Daeshon Hall. Having a complement is important, and the more opponents focus on Garrett (six tackles for loss, four sacks), the more Hall succeeds (nine TFLs, 3.5 sacks).

Jalen Hurts has avoided the level of mistakes that tend to cripple offenses led by young quarterbacks, but he has still struggled in obvious passing situations. Filtering out garbage time, he averaged just 1.9 yards per pass against Tennessee on passing downs (5-for-8 for 31 yards and a sack) and 5.9 against Western Kentucky. Alabama is up to fourth in Passing Downs S&P+ — the window of Hurts’ freshman mistakes seems to be closing — but A&M might impede Alabama’s run game and force Hurts to make plays on second- or third-and-long.

Actually, let me rephrase: A&M has to do that.

4. Special teams make a difference.

Alabama has returned three punts for touchdowns, and punter JK Scott has been as deadly as ever, averaging 47 yards per kick. But place-kicker Adam Griffith has still been inconsistent (Bama ranks 82nd in FG efficiency), and the Tide’s returns have been all-or-nothing.

A&M hasn’t gotten particularly consistent place-kicking, but the Aggies are in the top 40 in every other category: punts, kickoffs, punt returns, and kick returns. The Aggies could use special teams to keep up in field position, even when the offense has some inefficient moments. The longer you can keep Bama from tilting the field, the better.

5. Knight pretends he’s in New Orleans.

Photo by Kevin C. Cox/Getty Images

"Yes, having a mobile quarterback is OK if you have anything else. It's the icing on the cake. Tennessee showed it last week with Josh Dobbs, icing without any cake is just icing in a bowl, and you're not going to beat Alabama with icing in a bowl. To me, the only way to beat Alabama is to stand there man-to-man and be just as physical as they are."

— CBS’ Gary Danielson

The last time Knight faced Alabama, he became an exception. Bama never loses against teams with less-than-efficient offenses. The only time the Tide have lost to a team that ranked worse than 40th in Success Rate+ was when Knight’s Oklahoma did the deed. The Sooners still ranked 43rd in Success Rate+ that year, but Knight transcended the laws of time, space, and his own body.

Knight came to New Orleans having completed only 52 percent of his passes with a 105.6 passer rating. And against one of the best defenses in the country, he completed 32 of 44 for 348 yards, four touchdowns, and one interception. He had two 100-yard rushing games in 2013, but against Bama, he escaped the pocket and scrambled, buying time for his receivers.

That game made Knight a 2014 Heisman contender, and the hype ended quickly. By 2015, he was Baker Mayfield's backup.

He now gets a chance to create a career bookend.

His 2013 OU receiving corps was strong, led by senior Jalen Saunders and sophomore Sterling Shepard, and he got a huge Sugar Bowl performance from his No. 3, Lacoltan Bester (six catches, 105 yards).

His 2016 A&M receiving corps is better. (Granted, so is Bama's secondary.) But the combination of explosiveness from Reynolds, Seals-Jones, and Noil, and potential efficiency from sophomore Christian Kirk, Williams, and senior Jeremy Tabuyo gives him more options than most quarterbacks have.

If he wants to transcend himself one more time, Saturday would be a good day to do it.