26 November 2017

Wildcat Keeps Sanu Perfect!

The Atlanta Falcons beat the Tampa Bay Buccaneers today, 34-20.  The play I analyzed for TuneIn's No Huddle took place early in the 2rd quarter and broke a 3-3 tie.  The Falcons faced a 3rd and 1 from their own 49.5-yard line.  Former Rutgers quarterback and Falcons wide receiver Mohamed Sanu (#12) was in the shotgun.  The Falcons had pulled the wildcat formation out of their playbook.  Running back Tevin Coleman (#26) was lined up to Sanu's left.  Julio Jones (#11) was in the left slot with the Bucs' Robert McClain (#36) lined up opposite Jones.  The screen capture below shows the formation and defensive set (click on image for a larger view).
Did the Bucs think Sanu would run for the 1st down?  If so, that was a costly mistake!

McLain looked like he got a little lost on the play.  He left Jones not long after the snap.  He turned to cover the wide out.  That left Jones in single coverage with Bucs safety Justin Evans (#21).  Not long after the snap, Sanu faked the hand-off to Coleman, but the ball was bobbled.  Check out the screen capture below as Coleman's right hip knocked the ball out of Sanu's hands (click on image for a larger view).
Sanu recovered the ball from the air and threw it 3.10 s after the snap.

By the time Sanu threw the ball, Jones was running at about the Bucs 33-yard line.  Though Jones averaged almost 16 mph during the entire snap-to-score play, he averaged 19 mph after the ball was thrown.  Sanu released the ball at 53.2 mph and 43.8 degrees above the horizontal.  The ball took 3.27 s to reach Jones.  Air resistance was about 19% of the ball's weight, which is why the ball landed in Jones' gut at 47.1 mph.  Check out the ball's arrival in Jones' gut below (click on image for a larger view).
Jones was falling when he caught the ball, but physics helped him score as his linear momentum took him into the end zone!  See the score below (click on image for a larger view).
Julio Jones may have hated watching yesterday's Iron Bowl, but he surely loved watching that football fly at him from the wildcat position!  And how about Mohamed Sanu?  He is now 6 for 6 in his NFL career with 3 TD passes.  That makes for a PERFECT 158.3 passer rating!  Check out the trajectory of his latest TD pass below (click on image for a larger view).
Sanu's pass soared 16 yards above the turf before reaching Jones.  It was an amazing play for sure.

Chuck Nice from Playing with Science joined me on today's Check Down segment.  He did an amazing job setting up the play before I yapped about the physics.  He loved it when I noted that Sanu's spiral was about 10 revolutions per second or 600 rpm, which is one-and-a-third times faster than a helicopter's rotor blades!  Click here for the live bit we did for TuneIn.

22 November 2017

Extended Classic: Hail Mary!

Not long ago, while I was at Kenyon College for an invited talk, I recorded three extended segments for episodes of Playing with Science.  Tonight's episode may be reached via the link below.

It was a lot of fun talking more gridiron action.  Just in time for Thanksgiving!

20 November 2017

From Saints Sandwich to Touchdown!

No Huddle asked me to analyze a nice touchdown thrown by Washington Redskins' quarterback Kirk Cousins to Ryan Grant.  Unfortunately for the Redskins, the New Orleans Saints had a monster 4th-quarter comeback and won the game in overtime.

The play I analyzed took place late in the 3rd quarter with the shot clock winding down.  The Redskins faced a 3rd and 7 from the Saints 40-yard line.  Cousins (#8) was in the shotgun and just prior to the snap, the Saints sent both safeties in for a blitz into the middle of the Redskins' line.  Washington had seven blockers, including running back Samaje Perine (#32).  But the Saints had eight rushing the quarterback and it doesn't take a rocket scientist to know that 8 is greater than 7.  Kirk Cousins was about to get smashed!

The Saints' safeties had a running start on the blitz.  Cousins received the ball 0.43 s after it was snapped and the hungry Saints defenders were rushing for the sack.  Ryan Grant (#14) was on the right side of the Washington formation.  Check out the start of the play below from the screen capture I took (click on image for a larger view).
Grant sprinted to the right sideline as Cousins held the ball long enough for Grant to get open.  The left side of the Redskins' line broke down and Cousins was going to be blindsided by defensive end Alex Okafor (#57).  Cousins had taken four big steps back and threw the ball a full 2 s after he received the snap.  Just as he threw, he became the meat in a Saints sandwich as he got crushed by Okafor and safety Vonn Bell (#48).  Safety Rafael Bush (#25) piled on after the initial hit for added damage.  Check out the carnage below (click on image for a larger view).
Not much fun for Cousins, was it?  But he got the ball where it needed to be!  Cousins released a great spiral into low-Earth orbit at the speed of 46 mph at 30.7 degrees above the horizontal.  The ball traveled just over 38 yards in total horizontal distance, reaching a maximum height of about 8 yards above the turf, and took 2.1 s to reach Grant.  It landed in his hands at about 41.6 mph.  An air resistance force of about 15% of the ball's weight was acting on the ball while in flight.  Check out the graph below of the ball's trajectory (click on image for a larger view).
Grant had run past two unsuspecting Saints defenders and was wide open for the catch.  Check out just how open he was (click on image for a larger view).
Where was the defense?!?  All that was left for Grant was a stroll into the end zone with perhaps a little taunting thrown in.  After scoring, he tossed the ball into yet another low-Earth orbit.

For the audio on TuneIn Radio, click here.  Gary O'Reilly of Playing with Science joined me on the show and did a wonderful job setting up the play.  During my analysis of the play, I was interviewed by Alissa Smith of the Lynchburg News & Advance.  Gary O'Reilly was kind enough to give Alissa a few comments for her story.  Click here for the story that appeared in the Monday, 20 November 2017 edition of the paper.

12 November 2017

A Great Fake Punt!

For this week's appearance on TuneIn Radio, I got to discuss a great fake punt in the Jacksonville Jaguars' overtime win against the Los Angeles Chargers.  At the end of the first quarter with no score, the Jaguars were lined up for a punt.  It was 4th and 7 on their own 44-yard line.  Brad Nortman was set to receive the snap from long snapper Matt OvertonCorey Grant was behind the Jaguars' line to the right of Overton.  Check out the screen capture I got of the formation below (click on the image for a larger view).
I circled Nortman, Grant, and Paul Posluszny, who followed my yellow arrow into an incredible block.  Nobody was lined up across from Overton, and thus a lineman didn't notice that Overton was ever-so-slightly angled toward Nortman's right.  He would direct snap the ball to Grant.  Check out the hole that the Jaguars' line opened up for Grant, and note Posluszny's great block to seal the side of the hole to Grant's right (click on the image for a larger view).
Notice Grant is headed toward the massive hole as Posluszny runs right in front of him.  Grant had faked to his right to give Posluszny time to get in the hole for the seal block.  Nortman rolled out to his left to help sell the fake.

The Chargers had two shots at stopping Grant.  The first was by #40, Chris McCain.  Grant stiff-armed McCain at the Jacksonville 45-yard line as McCain dove toward Grant.  The problem with McCain's tackle attempt is that McCain's force mostly pulled downward on Grant's legs.  That wasn't going to alter Grant's forward linear momentum!  Check out the screen capture below (click on the image for a larger view).
McCain tried for Grant's feet, but Grant stabilized himself just a like a tightrope walker does.  Notice both his arms are extended outward.  That makes it harder to move Grant's center of mass outside his shoes, which would cause a gravitational torque to make him fall.

The second and last hope for the Chargers was #20, Desmond King.  He had an open-field shot at Grant near the Los Angeles 42-yard line.  But once Grant spied King, Grant shot to his left.  When King drove for Grant, Grant hurdled over nine feet horizontally to avoid having his legs taken out.  Look at Grant's athleticism below (click image for a larger view).
King dove, but Grant leapt to daylight.  Once Grant cut hard to his right at the Los Angeles 35-yard line, he outran the defense to the goal line.  Those hard cuts can lead to well over 100 pounds of force on a running back's legs.  It's no wonder the average career length for an NFL running back is only about four years!

What I especially loved about the play is that it took nearly 11 seconds to complete.  Someone could have jogged 10.6 mph along the sideline at the snap of the ball and gone 56 yards to the goal line in the time it took Grant to score.  Grant was through the initial hole at 15 mph, and then hit a maximum speed of about 19 mph halfway into Los Angeles territory before scoring at nearly 18 mph.  A sideline jogger that went 56 yards would have watched Grant run a total of about 85 yards!

Chuck Nice of Playing with Science joined me on today's radio segment.  Chuck did a great job setting up the play and then I yapped some physics.  Click here for our segment on TuneIn's No Huddle.  It was a lot of fun talking football physics!

11 November 2017

Return from Kenyon College

I returned from my visit to Kenyon College today.  Friends and colleagues know why the trip was difficult for me.  Kenyon College has been a special place for me since 1999.  Unfortunately it now represents a place of broken promises and betrayal.  What helped me considerably was the warm reception I received upon meeting up with former colleagues.  It was great chatting with old friends again.  I also enjoyed meeting new people and spending a few minutes discussing my research with Kenyon's bright physics majors.  I had fun giving my talk.  The photo below shows me a couple minutes before my talk began (click on the image for a larger view).  Pizza helped attract a few extra students!
The chalkboard shows some belated Halloween math I used to entertain people before I got introduced.  Nothing like a little mathematical nonsense to lighten an audience!

07 November 2017

Talk at Kenyon College this Friday

I will return this Friday to where my post-doctoral career began, Kenyon College in Gambier, Ohio.  There are many reasons why I look forward to being back at Kenyon, but there are several personal reasons why the trip will be difficult for me.  I'll do my best to put those reasons aside and have a great trip to a place that still means a lot to me.  I certainly look forward to discussing three of my research areas with the good people at Kenyon.  Either click here or on the poster below for information about my Friday talk.

06 November 2017

Great Blocking for a Great Touchdown!

The Philadelphia Eagles rolled over the Denver Broncos yesterday to the tune of 51-23.  Gary O'Reilly and I represented Playing with Science on yesterday's No Huddle segment on TuneIn, during which I analyzed Jay Ajayi's impressive 46-yard touchdown run in the second quarter.  Click here for the No Huddle segment.

Ajayi's touchdown run was so fun to analyze that I decided to write a bit more in my blog post.  Linear momentum, forces, and the laws of physics played crucial roles in the touchdown, like they do in most everything else that happens in the world.  Look at the screen capture below for the start of the play (click on the image for a larger view).
The Eagles have 1st and 10 at the Broncos' 46-yard line.  Quarterback Carson Wentz is in the shotgun and Ajayi is lined up on Wentz's right.  Note there are four defensive lineman and five offensive lineman.  Eagles' center Jason Kelce is not lined up against anyone.  Kelce is about to play a major role in the play with some key blocking.  Before that, he had to snap the ball to Wentz.  The ball took about 0.4 s to reach Wentz, which is about the time it takes for a major-league fastball to reach home plate.  Once he snapped the ball, Kelce pulled to his left, Ajayi took two strides to his left to receive the ball from Wentz, and then he witnessed the most beautiful blocking open up before him.  Check out the blocking in the image below (click on the image for a larger view).
Eagles' left tackle Halapoulivaati Vaitai had Broncos' outside linebacker Shane Ray (#56) blocked.  See the yellow circle in the above screen capture.  Eagles' left guard Stefen Wisniewski had Bronco's defensive end Shelby Harris taken care of.  See the orange circle in the above image.  Look at the hole Ajayi is about to run through!  After getting the ball from Wentz, Ajayi needed just five strides to get to the hole.  Note the white arrow on lead blocker in the hole, center Jason Kelce.  He has his eyes on Broncos' strong safety Justin Simmons.  Take a look at the blocking scheme from another view (click on the image below for a larger view).
That's quite a hole, right?  The Eagles' lineman employed their intuitive physics knowledge of linear momentum to set up the great run.  Isaac Newton taught us that a net, external force is needed to change an object's linear momentum.  The product of an object's mass times its velocity is an object's linear momentum.  Beefy lineman have lots of mass and thus need lots of force to stop.  A couple hundred pounds of force to stop a defensive lineman are not out of the ordinary.  Offensive lineman intuitively know that linear momentum and force are vectors, which means they have directions as well as magnitudes.  Keep that in mind for the end of the play.

The great line blocking allowed Ajayi to hit the hole at a speed of about 19 mph (31 kph).  He was able to maintain that speed while running down the left sideline.  While running toward the goal line, Ajayi's linear momentum was pointed right at the goal line.  Broncos' free safety Darian Stewart was Denver's last hope on the play.  Unfortunately for Stewart and Denver, linear momentum was working against them.  Check out the screen capture below as Stewart hit Ajayi at the Broncos' 3-yard line, just below Ajayi's hip (click on the image for a larger view).
Stewart hit Ajayi with a force nearly perpendicular to Ajayi's linear momentum.  That certainly changed Ajayi's linear momentum, but mostly perpendicular to the left sideline.  Despite a force of several hundred pounds over less than 0.1 s, Ajayi's linear momentum change was mostly toward the out-of-bounds area.  That works great unless an athlete like Jay Ajayi is a couple yards from glory and he is able to contort his body.  He still had much of his linear momentum that was pointed toward the goal line after the hit.

Just as he was hit, Ajayi rotated toward his right.  That ensured that after he was hit, his ball-carrying left arm would be above his body and ready to pass over the orange pylon for a touchdown.  See what I mean in the screen capture below (click on the image for a larger view).
From the terrific blocking at the start of the play to Ajayi's contorted body over the pylon, linear momentum was the 12th man on the field for the Eagles!