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The Essential Smart Football Review: Constraint Plays And Mobile Quarterbacks

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In case you haven't heard, Chris Brown of the wonderful website Smart Football recently wrote a book, The Essential Smart Football. It's an excellent introduction to a lot of the X's and O's that shape modern college football. If you're a fan of the game and want to learn more, be sure to pick up a copy.

Well, we here at One Foot Down devoured the book, and our own Eric Murtaugh asked me to answer some questions relating the topics in the book to the Notre Dame Fighting Irish. That isn't to say I'm as good at this as Chris Brown. In fact, don't think of this as "Smart Football," think of it as "Moderately Intelligent Football," or "IQ of 101 Football."

I'll be answering 2 or 3 questions every week or so until I exhaust Eric's questions, but if anyone has a topic they'd like me to cover, feel free to throw it up in the comments.

Let's begin.

1. Explain what constraint plays are and why Notre Dame's offense would open up and be more productive if they could run them more effectively.

Constraint plays are plays that punish the defense for cheating. When the safeties start to creep up to the line of scrimmage to stop the run, a play-action pass can punish them with a pass over the top. When the defense drops eight into coverage, a draw play can go for big yards. Constraint plays are not part of the regular offense; they’re used to force the defense to "play honest" when they try to take a certain play or type of play away.

Every offense uses constraint plays. In the flexbone triple option offense Navy runs, one of the slot backs goes in motion before every play, usually in the direction of the play. But if the defense starts to cheat and flow in the direction of the slot back’s motion, Navy will run a reverse.

The spread offense is known for its use of constraint plays. They don’t make up the entire offense, but they’re an important part of the gameplan for most spread teams. The spread is very unique in that it can be very run-heavy, very pass-heavy, or very balanced. No matter which way an offense leans, it needs to use constraint plays to keep the opposing defense off balance. The spread only uses one back in the backfield and typically one tight end at most, leaving the offense susceptible to the blitz.

It’s all about math. If the defense puts seven or eight defenders in the box to stop the run or to blitz the quarterback, the offense can use a quick bubble screen to get the ball to the outside away from the rushers. If the defense drops eight defenders into to coverage to stop the pass, the offense can run a draw.

Notre Dame’s offense is fairly balanced with a slight propensity for the pass. The Irish get a lot of mileage out of the running back draw and quick bubble screens, but never seemed to be able to use opponents’ gameplans against them. It became fairly obvious as the season went on that teams realized they could shut down Notre Dame if they loaded up on the run on first and second down and then dropped eight into coverage on third down.

Ideally, Kelly would just have Tommy Rees beat the defense over the top on first or second down by throwing to Michael Floyd or Tyler Eifert, but Rees just wasn’t very good at making those throws. Compounding the matters, Notre Dame’s receivers just weren’t very good at blocking on bubble screens. Usually, the screen would be thrown to Floyd because of how big and physical he is, but the other wideouts, especially TJ Jones and Robby Toma, struggled at making good blocks on defensive backs. The other option was to put Tyler Eifert out there to block, but putting Floyd and Eifert on the same side of the field will draw a lot of attention and defeat the purpose of the bubble screen. Essentially, the Irish offense was stuck in neutral and wasn’t very good in the second half of the season.

But there is hope. A mobile quarterback almost acts a constraint unto himself. Even if he isn’t Denard Robinson-level explosive, a quarterback who can run can cause a lot of problems for a defense. If the defense has to keep an eye on the quarterback at all times, then fakes, misdirection, and option plays can open up the running game. Play-action and bootlegs can become dangerous weapons in the passing game. And an old-fashioned QB draw can make going five-wide very difficult for the defense to defend. This is the dimension Andrew Hendrix and Everett Golson bring to the position.

But that isn’t to say Tommy Rees is a lost cause. He’s never going to have a cannon of an arm like Jimmy Clausen, but if he can learn to be more accurate on deep throws and at least make the defense respect the pass – even without St. Michael out there – then the offense will open up again.

2. Explain how in the spread a quarterback must be a running threat, and how constraint plays are used to keep defenses in a Cover Two in order to open up the run game and keep an advantage for the offense in the box. Discuss Rees' role in the offense and how his skill set affects the role safeties play in containing the Irish offense both through the air and on the ground.

I spoke about this in the first question, but it bears repeating: a running quarterback can act like his own constraint play. From a rather basic standpoint, a mobile quarterback forces the defense to account for the QB on every play.

What does that mean? Let’s look at Andrew Hendrix’s performance against Stanford last season. He didn’t exactly light the world on fire that game, but he was excellent in the running game. Look at the second highlighted play. On 3rd and 9, Stanford decided to bring only three rushers and drop everyone else into coverage. Look at the wide open area in the middle of the field.


Rushing three and dropping eight on third and long was Rees’s kryptonite last season, but it doesn’t work as well with a QB who can run. Hendrix took off on the QB draw and got the first down easily.

If you want another example of how a mobile quarterback can affect defense gameplans, watch the Champs Sports Bowl again (as painful as that may be). EJ Manuel finished the game with -20 yards rushing – mostly thanks to five sacks – but is known as player who can pick up yards with his feet. On almost every third down, Bob Diaco had either Harrison Smith or Manti Te’o spying Manuel. They weren’t in coverage defending anyone; they were just focusing on the QB. The offense has essentially removed a defender from the game.

But this seems a little backwards. How does forcing the defense to keep more defenders on the line open up the run game? The answer is constraint plays. If the defense drops a safety down close to the line to protect against the run, the offense should be able to take a shot downfield. If the linebackers crowd in tight, bubble screens will make them spread back out. And once the offense has more blockers than defenders the run game starts to take over, repeating the process.

Mobile quarterbacks are extremely useful in the spread offense, but how does a player like Tommy Rees fit in? When a quarterback can’t beat teams on the ground, he needs to be an accurate passer. There are only so many ways to run the ball out of spread formations if the quarterback is not involved, making it difficult to run the ball 40 times a game. Therefore, the QB needs to be a weapon in the spread.

A lot of Irish fans probably remember the 2009 Cincinnati team and wonder why ND can’t put up numbers like that. But if you compare Tommy Rees’s 2011 numbers with Cincinnati’s QB, Tony Pike, they compare very favorably. Pike completed 62.4% of his passes at 7.5 yards per attempt. Rees completed 65.5% of his passes at 7.0 yards per attempt. Of course, Pike threw 6 interceptions, while Rees threw 14.

The difference between the two quarterbacks is that Pike knew the offense from top to bottom and made great decisions; Rees tended to make bad throws and fit the ball into tight windows. Rees is entering his third year at Notre Dame and hasn’t known any system other than Brian Kelly’s. He can get better and could become a very capable quarterback for the Irish. He just needs to stop throwing picks in the end zone.