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Graphing the Tide: USC

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Taking an honest, data-driven look at the Tide’s supposed-dominance of the USC Trojans.

NCAA Football: Alabama vs Southern California Tim Heitman-USA TODAY Sports

Author’s note: many of you probably remember Saxon’s excellent “Charting the Tide” series from seasons past. Well, autumn is upon us and football data is starting to fall from the trees. While we won’t be getting into all the metrics we explored with Saxon, we’ll still be taking a quantitative look at each game this season. Plus, there are pretty graphs. People like pretty.

The Tide seemingly reamed the USC Trojans last weekend to the tune of 52-6, but don’t let the raw box score fool you: the metrics are calling this one a weird week-one game for a team and coach that traditionally values consistency and efficiency. Before we get into it, let’s talk about the metric definitions: for now, we’re just working with two.

Metric definitions

  • A "successful" play, as defined by Football Outsiders, is basically when a play gains enough yardage to keep the offense on track, i.e., 50% of needed yardage on 1st down, 70% on 2nd, or 100% on 3rd/4th.
  • A "big play" (aka an "explosive play") has different definitions depending on the analyst, but I use a generous one: a run of ≥12 yards, or a pass of ≥16, is a big play.

So let’s get into it: our first chart is a breakdown of success rates and big play rates on Offense.

Success rates, big play rates

Big play rate (XR) and Success rate (SR)

* NCAA average SR = 42%

Not seeing a chart here?

Anyone who watched the game could tell you that the Tide had a rough 1st quarter, and boy does that show up in the success rates! The average NCAA success rate is around 42% (IIRC)... and while Alabama averaged out close to that (ish) for the entire game, the first half sticks out like a sore thumb. In fact, the only successful Tide play of the first quarter was the very first play: the Stewart sweep around the outside that picked up 17 yards.

Fortunately, the defense did their part: after USC’s relatively-respectable first quarter (including that big pass to Darreus Rogers over Anthony Averett on the first drive), they were summarily shut down. The next successful play they ran (after several attempts) was also an explosive one: a 16-yard pass to Steve Mitchell towards the end of the first half. That USC didn’t start hitting average success rates until garbage time (basically the whole 4th quarter) is a testament to Alabama’s defensive strength in this one.

Once the defense gave the Bama offense some breathing room, things opened up into above-average (and fairly explosive) second half. That third quarter (as well as our third quarters in both of last year’s playoff games) is especially interesting given some of past Bama team’s struggles in the 3rd quarter (think 2014).

Plays by outcome

Unsuccessful, Successful, and Big play

Not seeing a chart here?

This helps us see the flow of the game with more granularity: instead of looking at averages over quarters, we’re looking at every play by “quarter quintiles” (breaking up each quarter into 5 parts of game-time, 15:00-12:00 being the first). Looking at that first half again, this really hammers home the struggles the offense was having early on: after the initial Stewart sweep, that’s five quarter-quintiles (basically a whole quarter’s worth of time) without running a successful play on offense!

Things started coming around in the second quarter, though, due to some combination of factors that surely involve coaching, O-line soul-searching, and Jalen Hurts. While efficiency still left something to be desired, at least the big plays were paying off: the 1st half Jalen Hurts - ArDarius Stewart connection and Damien Harris’s breakout run led to the Tide’s first two scores. (Each of those events happened again in the 2nd half, too).

As we saw before, things really opened up in the second half. Especially notable here is the action in the late 3rd and early 4th quarter: that could be interpreted as a one-two punch between Blake Barnett (big plays) and Bo Scarbrough (efficient runs). Around the same time, USC’s Sam Darnold (the young backup QB who pushed Max Browne for the starting spot) came in to complete some successful passes. While some of this can be attributed to garbage-time factors (second-string defenses, high-risk playcalling), it’s interesting to see some of these QB and RB battles make some waves during the game.

Running and Passing (#RTDB)

Run rate (runs ÷ total plays), cumulative

Success rate for runs and passes, cumulative

* NCAA average SR = 42%

Not seeing a chart here?

Running the dern ball: a Gump story. Work with me on this one: these are the cumulative rates for the Tide’s running and passing: the numbers at the right end of the graphs represent the entire game, after everything has settled.

This is a weird one! Explosive passing plays were the lifeblood of the team for much of this game (think, Hurts-Stewart x 2, Barnett-OJ, Barnett-Dieter), but Bama wasn’t a very efficient passing team: in fact, we had a 0% success rate on passing until midway through the 2nd quarter. Ouch.

After the initial Stewart sweep, rushing didn’t look too hot either in the 1st half. Fortunately, a relatively strong running game the second half brought Bama back to slightly above average for the game. There are a few things going on here: for one, Jalen Hurts was running a fair amount, including two scores in the second half (those #HotTakes about his passing stats would do well to note that his legs are putting in some work at QB, too). Also, you won’t see Scarbrough on the ESPN highlight reels (aside from his short punch-in touchdown, maybe) but he was doing some of the heavy lifting during the second half, helping to bring those run SR averages up. His efficiency balanced with Damien Harris’s apparent explosiveness could grow into a fruitful one-two RB punch later in the season. Here’s to hoping.

The passing stats also improved during the second half (nowhere to go but up...). You could chalk that up in part to Barnett’s second entrance into the game, but Kiffin was also choosing to run the ball at an increasing rate throughout the game (between RBs and QBs), which takes pressure off the passing game and reduces the overall number of pass attempts we’re talking about.

Parting thoughts

  • Looking at these numbers, it makes sense why Saban was grumpy after the game. Yes, it’s funny to gripe about performance after a 46-point victory over a (allegedly) quality opponent, but the way Alabama got these points was sporadic and often unreliable. Hopefully the offense improves its efficiency over the next few games, as we don’t want to go “big play vs big play” against a team like Ole Miss.
  • On the other hand, the defense was great. USC had a few spurts of success, but even the best defenses give up those. This was a pretty thorough blanketing for an offense we’d heard some good things about.
  • ArDarius Stewart was the Tide’s “X factor” for much of the night, and was featured in 3 of our first 4 big plays. This may be in part because of the USC’s focus on the “headlining” receivers in our group (Foster, Ridley, and OJ), but don’t take too much credit from Stewart: he was showing up mysteriously behind opposing DBs at several points last year, too, and he’s obviously earned Hurts’s trust.

The charts are pretty broad for now, but they do give some non-gumpy perspective. Let me know what you think in comments below. Thanks all and Roll Tide!