Resolving the Parallax Error

Submitted by santy on

EDIT: TLDR - From what I can estimate the tip of the ball crossed the plane of the first down (as I define it) by about two inches. The margin of error indicates there is a possibility it might not have, but that's unlikely :(

 

THE SPOT has been debated to death. Both OSU and us have provided camera angles that "prove the result", without really doing so because of the following resons: When a still camera image is analyzed, it begs the question "was that taken at the instant of forward progress by Barrett?". When a moving image is analyzed, the issue of parallax error is not resolved fully enough, even for #ThePerfectAngle. It is pretty important to do so simply because it is such a close call.

The most important variable to resolve is Time. Now both wolverines and buckeyes have all seen this GIF and drawn various conclusions and posted screenshots that vindicate their arguements and show their gross negligence of parallax error. 

 

Let's a closer look at this. I've taken the liberty of running through the GIF frame by frame and have isolated the instant where Barrett has made the most forward progress. This would be Frame 53 shown below:

Okay, so now we've got Time out of the way. This image has been posted by many buckeye fans because they can just draw a line along the 15-yard line and say that the tip of the ball is clearly past that line demonstrating that education system in ohio has yet to incorporate the concept of a parallax error in the school syllabus. 

The most important step in this is to determine exactly where along the width of the field the ball is at this instant. If we can do that, we can resolve the parallax. Fortunately we have a few clues. Here is Barron's picture from Ace's game recap:

It's a really useful shot because of when it was taken. The positioning of Jourdan Lewis' feet correspond to Frame 51/52 of the GIF above, which places this at almost the instant of most forward progress. The first thing this shot tells us is that the front tip of the ball is lined up vertically over Barrett's left pinky finger from this angle. [EDIT: I mean to say that the ball, Barrett's hand, and Barron's camera are all on the same vertical plane. The blue lines below are parallel to the intersection between this vertical plane and the field.] 

The relative positioning of the hash marks in the bottom right corner actually give us a pretty good estimate of this angle shown by the light blue line. It also tels us that the ball is slightly past Wormley's right arm.

If we assume that Barron was sufficiently far away, we can slide that blue line down to the outside of Barrett's left hand we know where along the 15 yard line the ball would have had to be in order to cross the first down.

Here is where things start to get a little tricky. Where exactly is the plane for the first down located relative to the 15-yard line? If we assume that it is at the border of the 15-yard line facing midfield and assume that the TV camera that recorded the GIF is not rolled to either left or right, we can resolve the prallex error. First we draw the position of the presumed boundary for the first down (shown in pink):

The intersection of the pink and blue lines indicate the position of the ball projected down onto the field, if it had crossed the plane for a first down. Again, if there were no roll variations in the camera that recorded the GIF, we can simply draw a vertical line (in light green) from this intersection to mark the boundary of the first down with the parallax error resolved:

I've drew the green line with a gap around the area where the ball should be. I've run through the GIF frame by frame several times, and there is a light spot only a couple of pixles big to the left of Wormley's forearm and I believe that is the white stripe of the football. You'll notice on Barron's picture that the stripe is facing up so it makes sense that it should be barely visible from this angle. You can also see that it is literally a pixel past our hypothesized first down line. Given the dimensions of a typical football, that would make the tip 2-3 pixels past the green line. 

 

It really depends on where exactly you define the plane of the first down to be. Is it the edge of the 15-yard line as I drew it? Is it on the opposite edge? Is it right down the middle? FWIW, the width of the line is 9-10 pixels on the GIF.

 

P.S. With regards to the tweet below,

 

 

 

The frame in this video that corresponds to Frame 53 in the GIF above (I used the positioning of Gedeon's legs to figure this out) has OSU's #73 obstructing the view so it's not very conclusive, also the ball was under Wormley's arm and part of it was past his arm as clearly seen in Barron's photo.

Comments

In reply to by ijohnb

Laser Wolf

November 28th, 2016 at 8:18 AM ^

I agree. I think that's an extremely tough call to make in real time and not enough to overturn. I have no problem with the spot.

The other calls are infuriating but nothing we can do now except root like hell against Washington and Clemson.

TrueBlue2003

November 28th, 2016 at 4:03 PM ^

played PSU at Pitt, not Happy Valley.  They played Clemson at Clemson's stadium nicknamed "Death Valley" which it appears is the game in reference, so Death Valley would be correct.  If the reference was to the game against PSU, the correction would be that it was not at PSU but rather Pitt.

Mitch Cumstein

November 28th, 2016 at 7:56 AM ^

I think the spot/review is a red herring. The 10+ blatantly missed holds by their oline and DBs throughout the game, as well as the PI inconsistency should be where our outrage lies.

unWavering

November 28th, 2016 at 8:19 AM ^

It doesn't fucking matter. We lost, and we had a lot of opportunities to win the game, refs nonwithstanding. It sucks, but it is what it is, and it's not changing at this point. We just need to move on and win the next game, whatever that may be. I think there's very little question that Michigan is one of the top 4 teams in the nation at this point. Let's see if the committee agrees.

M-Dog

November 28th, 2016 at 8:30 AM ^

The fact that we have to spend hours of video work to try to resolve "Parallax Errors" 2 days after the game is over indicates that there was no way the call was ever going to be overturned in overtime in Columbus. It was just never going to happen.

However . . . the value of all these Zapgruder films (and Harbaugh pointing out obvious referee bias) is for the broader media and CFP committee audience.  And they are starting to take notice.

It has become absolutely clear that Michigan and Ohio State are completely even teams.  CFP #2A and #2B.

What we are looking for is "Jury Nullification" in the form of the CFP committee putting Michigan in the CFP for the same reason they would put OSU in.  Put both of us in or neither of us. 

The Refs were never going to change this call, but the CFP committee can de-facto change it.

 

kevin holt

November 28th, 2016 at 8:50 AM ^

Also perhaps the proper narrative shouldn't be "these refs fucked up" but rather "these refs lacked the technology to decide properly." Maybe we should be making a stink for change rather than bitching about the call. They need more camera angles at a minimum and preferably put chips in the ball to have a computer review of the spot. Wouldn't change anything except the crucial review process or challenges.

BlueLikeJazz

November 28th, 2016 at 8:47 AM ^

(I know, they suck, but are the epitome of "media taking notice")


Herbstreit said he thought Michigan deserves to be in the playoff, and Louis Riddick said he thought the most egregious (non)call was the non-PI on Perry in the 2nd OT. I'm not holding out hope, but the idea that M got a bitvrobbed and deserves a shot definitely has legs.

Durham Blue

November 28th, 2016 at 10:12 AM ^

Awesome points.  It IS absolutely clear that Michigan and OSU are dead even.  So if the committee's job is to select the best four teams in the country and OSU is considered second best then by default Michigan must be one slot below them.  I am hoping beyond all hopes that it's #2 vs #3 again for the right to play in the national championship.

SaveTheRivalry

November 28th, 2016 at 8:28 AM ^

bitching about the pass interference call in overtime from 2002. Is that going to be the same with all of you? I learned to walk away from football and sports stories/rankings after a loss. Ped State won and I stopped watching football for three weeks and volunteered to work all day Saturday to avoid a melt down from what was the best and worst game against Michigan ever. I realize it sucks. I said growing up, after watching John Cooper shit away great team after great team against you guys, that I would crash Michigans team bus on the way to Columbus if I was late in life and hadn't yet seen a National Championship by Ohio State. It's a rough patch for you guys. But it will come full circle. Sadly. So BUCK up! And pretend to be unfazed by it all because.....

Maison Bleue

November 28th, 2016 at 9:24 AM ^

Please go away, you're not helping. It's one thing to lose fairly, (like you did to PSU or like the UM-OSU game last year) I can get over that. But when you lose because of biased referees, who happen to be fans of the team you just lost to, that is anger that may stick with me for a long time. It's anger for the men that worked their ass off to be better than their opponent, it's anger for an oft-jilted fanbase and it's anger that once again an OSU team gets bragging rights about something they don't deserve. You don't get it, you never will, so again, please just go away.

P.S. You thought about crashing a team bus over football? You need help, like lots of it. You are the last person that should be telling people to get over it.




Sent from MGoBlog HD for iPhone & iPad

Ghost of Fritz…

November 28th, 2016 at 8:30 AM ^

Appreciate the work that went into the OP.  Very interesting stuff.

To me the photos in the OP further confirm that Barrett was short.  The ball never advanced as far as the crook of Wormley's bent arm. 

But I keep returning to the concept that the ball as not visible in real time to the line judge.  It has obscured by Barrett's helmet and back for one line judge, and by Wormley's body (and other players too) by another line judge.

The spot was a guess. 

The 'guess' theory is confirmed by where the officials actually spotted the ball--with the center of the ball resting on the middle of the 15 yard line. 

In real time and with the best photos and videos that have come out since, there is no way the ball advanced such that the middle portiion of the ball got to the middle of the 4 inch wide 15 yard line. 

The various no-calls on holding and no-call in the clear pass interference in M's possession in the 2nd overtime are beyond any dispute.  Those mistakes were also decisive. 

 

 

 

 

ama11

November 28th, 2016 at 8:32 AM ^

Put chips in the tips of the ball and build sensors into the field and this won't happen again. Technology can help eliminate some human error, or in this case bias. Nowadays how hard could this be to implement?



Sent from MGoBlog HD for iPhone & iPad

Victor B

November 28th, 2016 at 8:40 AM ^

This pretty much confirms what I said yesterday when I noticed the ball was under and beyond Wormley's arm.  I was afraid that Barrett actually did make it based on how forward he was carrying the ball.    Without that picture it was hard to tell where the ball actually was.