Monday, January 19, 2015

College National Championship Postgame Analysis

All hail the college football playoff.  Instead of being subjected to an Alabama vs. Florida State BCS "championship" game (and don't even try to tell me that any other teams could have gotten into that game; Florida State for all its shortcomings was the undefeated defending champion, and Alabama is Alabama - you know, from the SEC) we got let those two go play an imaginary bronze-medal game.  Meanwhile the real championship was decided on the field (unless you like TCU).  I'd still prefer a ten-team tournament of conference champions, but wow, was this better than before.

That the underdog Buckeyes came away with the win wasn't a huge surprise.  In the last four years, Ohio State's recruiting classes have ranked #11, #4, #2, and #3 according to rivals.com (Oregon's were #9, #16, #22, and #26).  Oregon was also missing key contributors at tight end, offensive line, cornerback and receiver, though OSU was also down to third quarterback Cardale Jones (more on him later).  The surprise was the dominating fashion with which OSU dispatched a team that is used to dominating its own opponents.  The Buckeyes averaged 6.4 yards per play, possessed the ball for over 37 minutes (a statistic with little meaning against Oregon, but still), and won by 22 despite losing the turnover battle 4-0 (ignoring a meaningless Oregon interception on the last play).  Tailback Ezekiel Elliott rushed for a 6.8 yard average on 36 attempts while using only half a jersey.

Meanwhile, the vaunted Oregon offense was held largely in check.  Although they piled up 465 yards of offense and didn't turn the ball over, they were just 2-14 on third and fourth down, and scored just 20 points on five trips inside the red zone.  Surprisingly, a Ducks offense that is known for innovation seemed strangely low on ideas.  No Oregon non-quarterback attempted a pass, no designed laterals were thrown, no double reverses occurred.  Byron Marshall, a potential matchup advantage as a former tailback playing receiver, had only one rush.  Normally, Oregon's base offense and blistering pace are enough to keep most defenses off balance.  But Ohio State coach Urban Meyer is a spread guru himself and a close friend of the Oregon program, so the Ducks could have anticipated less confusion than normal.  Ohio State, being out of academic session during the 11 day layoff after the Sugar Bowl, was also allowed unlimited practice time instead of the normal 20 hour weekly limit.  Under these circumstances, a few trick plays would seem to be a useful asset.  OSU certainly knows about having some tricks ready; in their Sugar Bowl win over Alabama they used a reverse pass to jump start their comeback.  Even the great Nebraska and Florida State teams of the 1990s, who could beat anyone when everything went as expected, always had a trick play ready just in case it didn't.

More surprising than Oregon's offensive rigidity, though, was their stubborn insistence on playing their base defense.  Despite consistently yielding chunks of yards to the Buckeye ground game, Oregon's defenders remained in their base 3-4 Cover 4 alignment.  With their frontal defenders undersized and outnumbered, the Ducks were unable to generate either a consistent pass rush (their one "sack" of the game was actually a Winstonian scramble-fumble by Jones) or any serial success against the run.  

To be fair, there is wisdom in dancing with the girl who brought you to the prom.  The Ducks defensive philosophy all season has been to bend without breaking, limiting big plays by keeping the play in front of the defense, playing zone to keep the defenders facing the play, forcing the opposition to execute long drives, and stiffening in the red zone.  Although the opposition may gain yards against this strategy, over the course of a long drive a penalty, string of incompletions, or turnover would often get the Ducks D off the field.  Oregon's tall but light defensive ends are liabilities against the run but ideal for rushing the passer when the Ducks have the lead, which they usually do.  The problem was that Ohio State's running game was so successful, they were able to score quickly without much passing.  Despite the Buckeye playbook narrowing at times to just inside zone, sweep, and counter, the Ducks never adjusted and never stopped allowing chunks of yards on the ground (though they were in position to pick up the four turnovers that kept them in the game).  So, with the obviously unfair advantage of hindsight, what should the Ducks have done instead?

Bear Down

The team that gave Ohio State it's only loss on the season offers a starting place for ideas.  Virginia Tech, who would go on to finish 7-6 and fifth in the ACC Coastal Division, beat the Buckeyes 35-21 in Columbus on September 6th.  The Hokies slowed down the Buckeye ground game with a "Bear" front, a five-man defensive line that puts a nose guard and two tackles over the offensive center and both guards.

(Image from elevenwarriors.com)
The Bear front is named for the Chicago Bears, who used a defense called the 46 Bear under Buddy Ryan in the 1980s.  (The 46 is not the number of linemen and linebackers, it was just the jersey number of Doug Plank, Chicago's strong safety at the time and a key cog in the defense.)  The 46 is a truly innovative scheme that creates several problems for the offense, with the three interior linemen only its most obvious structural element.  Virginia Tech doesn't use the true 46 Defense here, but just covering the three inside linemen causes two big problems for the Buckeye-style run game:

1) The inside zone (and outside zone) play relies on double teams wherever the defense leaves a "bubble," or uncovered lineman.  The offensive linemen want to double their nearest defender, and then let one of the doubling linemen scrape off to a linebacker, creasing a crease for the runner to find and exploit.  But against a five-man defensive line, no lineman can help double team because each has a defender of his own to deal with.  As Homer Smith wrote, "if there are no linebackers, there is no zone play."


Inside zone versus 3-4 front.  For simplicity, this diagram omits extra blockers such as tight ends and h-backs, which Ohio State often uses.  These extra blockers may create favorable matchups but do not give the offense any extra numerical advantage, because they would each bring a corresponding defender into the play.  In fairness to Oregon, its Cover 4 scheme expects the two safeties (not pictured) to help fill against the run.  Still, the bubbles in the front are obvious.

Against the Bear front, the offensive and defensive lines have the same number of players, so the zone play has no bubble to exploit.  The result is that there is no natural crease for the runner.

2) The off-tackle counter and power plays rely on a double team at the point of attack, combined with a kickout block from a backside pulling lineman.  Against a bear front, the center can't block both the nose guard in front of him and the defensive tackle over the pulling guard, so he either has to call for help on the nose, creating a cascade effect that eliminates the double team, or the guard has to stay home.

The counter play uses a block down, kick out power scheme.  The running lane is created by the double team at the point of attack and the kickout block of the end man on the line.

The backside defensive tackle is a threat to disrupt the power play by shooting the gap and either dropping the runner for a loss or interfering with the pulling guard.  The center has to block back to protect this guard, but also has a nose guard to deal with himself.  Against a Bear the center can make a "TNT" call as shown to down-block the whole front and maintain the integrity of the play.  But this adjustment removes the double team at the point of attack and leaves the Mike free to run to the ball.

Of course, adding a player to the forcing unit means removing one somewhere else.  The Hokies took that player from the contain, playing Cover 0 or Cover 1 and daring Ohio State to beat them over the top.  The Buckeyes of September 6th couldn't.  Quarterback J.T. Barrett did not consistently beat the man coverage with throws downfield, in part because his offensive line could not give him time against the five-man rush.  He created a few plays with his feet, but not consistently enough to bring the Buckeyes back.  But two things changed between September 6th and January 12th: Barrett broke his ankle and was replaced by the big-armed Jones, and Devin Smith emerged as one of the more dangerous deep threats in the game.  Ohio State's offensive line also improved at pass protection over the course of the season.  By the time the championship game came around, it had become unlikely that Oregon, Virginia Tech, or anyone else could have stopped the Buckeyes with the same gameplan that worked early in the season.

Playing with Fire

If Cover 0 and Cover 1 had become too risky against the suddenly bombs-away Bucks, but sitting back in a 2-shell was overly conservative, then a 3-3 fire zone offers a middle ground.  At first glance, this coverage looks hopelessly unsound.  Not only do only three defenders have to handle the entire undercoverage (also true of Cover 4, btw) but because the undercoverage and contain both consist of odd numbers, the weakpoints in the two levels align, creating inviting lanes for receivers to run right through.  


Technique makes the coverage work.  The slot defenders do not spot-drop directly to the flat on the snap (although a few DCs, such as Manny Diaz, do teach spot-dropping in fire zone coverage), leaving their receiver free to run the seam.  If the inside receiver runs straight up the seam, the slot defender collisions him and "carries" the seam route until the depth where the free safety can cover it.  He then drops diagonally outside to cover the curl route before going to the flat (there are different ways to teach this coverage, and also exceptions to these rules for things like crossing receivers).

More fundamentally, the 3-3 coverage is a percentage play by the defense.  It allows five frontal defenders to stop the run and pressure the passer, while keeping a three-deep shell to prevent big plays over the top.  Unlike the Cover 0 and Cover 1 coverages used by the Hokies, it also keeps defenders in zone coverage where they can face the play.  This puts them in position to make a quick tackle if the offense completes a short pass, or to make the interception in the event of a tipped ball or overthrow.  You can't get something for nothing though, and this defense does allow large windows for the short passing game.

But Cardale Jones, for all his success as a short-yardage runner and long-yardage thrower, had not yet proven his ability to make consistently good decisions in a ball-control short passing game.  Furthermore, Oregon's odd front defense should adjust naturally to a Bear.

Just one of several ways to create a Bear front from a base 3-4.

All of which makes it so surprising the Ducks never made this adjustment, or any clear defensive adjustment, especially in the second half as the diminishing clock steadily reduced the downside of taking a risk.  With the benefit of hindsight, there are probably many things that Oregon could have done differently in this game.  Firing up a zone blitz coverage is just one.

Addendum: Barrett and Jones

With Cardale Jones announcing that he will return to school next year instead of cashing in his instant stardom by leaving for the NFL, Ohio State has an embarrassment of quarterback riches on its hands.  Braxton Miller, the two-time Big 10 offensive player of the year who missed the championship season with a shoulder injury, may decide to change schools rather than positions.  Since he is eligible to play immediately as a graduate transfer, he will be a highly desired free agent, possibly even by Oregon.  All J.T. Barrett did after Miller went down was lead the Buckeyes to an undefeated regular season and Big 10 championship.  Then there's Cardale Jones, who came on to win the Big 10 title game and both playoff games to bring home the national title.

If Miller came back to OSU as a halfback, the potential two-quarterback formations could drive opposing defenses... nuts.  But he probably wants to play quarterback and may not be willing to risk spending his final year as a backup, so he seems likely to transfer.  That leaves Barrett and Jones, which offer an interesting contrast in styles.  Barrett is the faster runner and more experienced player, but Jones offers much greater size and the bigger arm.  Although Meyer might normally prefer to put as much speed on the field as possible, the fullback-sized Jones, like former Meyer QB Tim Tebow, can bulldoze in short yardage situations.  This allows a hybrid runner/receiver like Percy Harvin or Chris Rainey to fill the halfback spot.  Such "four and a half receiver" formations put extreme stress on the defense and allow Meyer's offense to reach new heights.  Combined with Jones' arm, this would make him my choice.

Sunday, January 11, 2015

Patriots Bring the A-11 to the NFL

On Saturday, the Patriots were in trouble against the Ravens.  Trailing in the third quarter and struggling to move the ball against the Baltimore defense, New England coach Bill Belichick reached into his bag of tricks.  He ran several plays with only four offensive linemen, confusing the defense into leaving a receiver wide open:


(image stolen from SB Nation)

Before this play running back Shane Vereen (circled) declared himself as an ineligible receiver to the referee, who told the defensive captain.  As an ineligible receiver, Vereen can't go downfield, so he runs backward instead.  Tight end Michael Hoomanawanui, aligned where the offensive left tackle would normally be, sprints down the seam uncovered by the surprised defense.  The result is a fifteen yard pass from Tom Brady and a first down.

Ravens coach John Harbaugh was none too pleased.  Calling the play and the preceding substitution "clearly deceptive," he insinuated that the referees did not understand what had happened, and that the NFL may change some rules in the offseason to prevent this kind of thing happening in the future.  He even took an intentional penalty to prevent the Patriots from doing it on one play.

There is nothing illegal about what the Patriots did.  Only those players who align in the backfield or as one of the two end men on the line of scrimmage are eligible to catch a pass; the five "covered linemen" are not.  (On this play, Vereen is "covered" by Julian Edelman at the bottom of the screen, so he is aligned as an ineligible receiver, while Hoomanawanui is the end man on the left of the formation, so he is eligible.)  In the NFL, the offense normally has five players with ineligible numbers (50-79) on the field, to help the referees identify who can and can't catch a pass.  If they align with more or fewer than five such numbers, they must tell the referee who is or isn't eligible.

At first glance, this looks similar to plays you see from time to time where the offense uses an unbalanced formation to put a tackle out wide and hide a tight end at the tackle spot (LSU, Alabama, and Auburn have all done this recently).  But there's a critical difference.  On those plays, the offense still has the usual five ineligible numbers on the field, albeit in unfamiliar places.  On this play, there were seven players on the Patriots offense (counting Brady) with jersey numbers indicating they could catch a forward pass.  Vereen declared himself ineligible, just like when an extra offensive lineman comes on the field and declares himself eligible.  But when one lineman declares himself eligible, the defense can find him easily.  It's somewhat harder when a player reports as ineligible, leaving just a few seconds to determine by elimination the remaining five players who are eligible.  This is what got Harbaugh so worked up.

Belichick explained the formation this way after the game: "We ran it three times, a couple different looks. We had six eligible receivers on the field, but only five were eligible. The one who was ineligible reported that he was ineligible. No different than on the punt team or a situation like that."  Actually, when you put it that way, that sounds kinda familiar...


All Eleven


The A-11 offense was a short-lived high school offense based around a similar premise.  This scheme (the name is short for "all eleven eligible") used a spread formation with three groups (called "pods") of three linemen each, with two backs in the backfield side by side, all of them wearing the jersey numbers of eligible receivers.

(image from Wikipedia)

Before the snap, all players except the center would stand in the backfield.  Just before the snap, six of the players would step onto the line of scrimmage, "covering" five of them and making them ineligible receivers.  After the required one second, the ball would be snapped and the five eligible receivers would be free to go downfield, with the other five staying near the line.  Without enough time to adjust to the shift, the defense would often leave receivers running uncovered, just like Hoomanawanui.
(image from fishduck.com)
Normally, it wouldn't be legal to have eleven players on the field in eligible receiver numbers in a high school game.  But the A-11 creators took advantage of a loophole, the "scrimmage kick exemption."  Because the quarterbacks in the backfield were at least seven yards off the line of scrimmage, the A-11 was technically a kicking formation.  And because high school teams often use defensive players on kick coverage units, it makes sense that there was a rule relaxing the normal regulations around eligible receiver numbers on kicking downs.  But after two years of the A-11 turning the game upside down, the traditionalists had seen enough, and the National Federation of High School Associations voted in 2009 to close the loophole, restricting the scrimmage kick exemption to fourth downs.  (In the NCAA the exemption exists only on obvious kicking situations, presumably fourth downs or late in the half.)  The A-11 still exists as a (relatively) conventional unbalanced line formation, but the dream of "all eleven" football is dead, at least until fourth down.

But now, it looks like the Patriots may have resurrected it with their "punt team" offense.  The NFL is the only league that allows players to declare themselves eligible or ineligible.  Theoretically, there is nothing stopping the Patriots from going into their game with the Colts next weekend with eligible numbers on all of their players.  Before the snap, five of the players could inform the referee that they are ineligible, then scramble to the line and snap the ball.  

The creators of the A-11 hoped to change the game, but they couldn't overcome the powerful interests who wanted to keep it as it was.  Time will tell if the Patriots are powerful enough to succeed where they failed.