Spreadsheet: Actual vs Expected PSI Drop Based on Wells Report Data

Hi guys,

I made a spreadsheet which allows you calculate the difference between the expected and actual PSI drop based on the actual data, allowing you to manipulate assumptions such as the initial reading from each gauge. The justification for my default values are given below.
https://docs.google.com/spreadsheets/d/1QhGMoE80dWZaIFA00XYVDbUEoZ6g0G3CGzF6Muc72yI/edit?usp=sharing
https://docs.google.com/spreadsheets/d/1QhGMoE80dWZaIFA00XYVDbUEoZ6g0G3CGzF6Muc72yI/edit?usp=sharing

The Wells report was confusing, because of the fact that there were two different gauges, one of which read out values approximately .4 psi lower than the other. We'll call the gauge with the lower read-out Gauge A, and the one with the higher read-out Gauge B. According to the Wells report it is unclear which gauge was used for the initial measurements, but the balls were measured with both gauges at half-time. If you assume that the initial 12.5 starting psi for the Patriots was made with Gauge B, then the initial read-out from Gauge A would have been 12.1 psi. The spreadsheet allows you to change the values for Gauge A and Gauge B, but the starting value for Gauge A should always be 0.4 psi lower than for Gauge B.

The Wells report also stated that given a starting psi of 12.5, the balls would be expected to be between 11.3 and 11.5, or, if Gauge B was used for the initial reading, the balls would have read as being between 10.9 and 11.3 on Gauge A. The spreadsheet allows you to configure the expected psi drop. The default drop is 1 psi, which is on the conservative end of the results from the Wells report.

With these starting conditions, the average ball was 0.002 psi lower than expected, a result that is not statistically significant.

none of that matters now. Wells more likely then not probably considered using facts and more likely then not probably decided that just winging it would be good enough for all but new england fans.

As far as the rest of the world is concerned the patriots cheated, end of discussion.

THIS MAKES ME ANGRY. %!@%

Ted Wells just flat out chose to take a dump on scientific facts, while hoping that nobody noticed

Page 198-99 of the report (page 39 Table 10 of the Exponent report). Am I reading this right that they agree that the expected drop in pressure from 70 degrees to 48 is 1.13 for a ball filled to 12.5.

and on page 7 of their report, Table 4, the average measured drops at halftime between the two testing officials was 1.39 and 1.01.

So, basically, the numbers were what should have been expected?

Biggs1221 said:

Page 198-99 of the report (page 39 Table 10 of the Exponent report). Am I reading this right that they agree that the expected drop in pressure from 70 degrees to 48 is 1.13 for a ball filled to 12.5.

and on page 7 of their report, Table 4, the average measured drops at halftime between the two testing officials was 1.39 and 1.01.

So, basically, the numbers were what should have been expected?

Click to expand...

That's what I don't get...they're basing conclusions on the fact that the Colts balls didn't drop as much as the Pats balls. Why is that relevant, doesn't it stand to reason that maybe the Colts balls didn't actually start at 13? That the Colts balls were inflated at a lower temp than the Pats balls?

I feel like I'm taking crazy pills...everyone's talking about devoid-of-context text messages between two asshat ballboys and ignoring BASIC SCIENCE.

and on page 73 of the actual report, the pats balls, post game, that they inflated back to 12.5, were now at 13.5. So, they jumped up a whole psi?

Doesnt a lot of this not make sense?

It looks like the scientific evidence in the report is based on comparing what happened to the patriots balls compared to the colts balls.

Yet there is NO detailed analysis of differences in inflation temperature and sideline storage temp between the two sets of balls?

Biggs1221 said:

Page 198-99 of the report (page 39 Table 10 of the Exponent report). Am I reading this right that they agree that the expected drop in pressure from 70 degrees to 48 is 1.13 for a ball filled to 12.5.

and on page 7 of their report, Table 4, the average measured drops at halftime between the two testing officials was 1.39 and 1.01.

So, basically, the numbers were what should have been expected?

Click to expand...

Yes, the bulk of the case was actually based on the fact that the Colts balls, while they experienced a drop, did not experience as large of a drop as the Patriots' balls. The Wells report was almost certainly missing something with respect to the Colts footballs, because if the balls were at 13.0 psi at the beginning of the game, there is no way in hell that one of the balls could have been 12.95 psi at half-time. The Colts ball temperatures can be explained scientifically with the following set of assumptions, with high precision:

• The Colts' balls were initially set with the Logo gauge (Gauge B).
  
• The balls dropped approximately 1.2 psi due to temperature, as with the Patriots balls.
• The balls subsequently rose in temperature ~.6 psi due to being brought back inside to be measured, as seen on page 51 of the Exponent appendix. The Patriots balls were measured first (page 68), so they experienced less of this effect.

The Patriots balls can be explained scientifically with the following assumptions, with high precision:

• The Patriots' balls were initially set with the non-Logo gauge (Gauge A).
• The balls dropped approximately 1.2 psi due to temperature, as with the Colts balls.
• The balls subsequently rose in temperature ~.2 psi due to being brought back inside to be measured, as seen on page 51 of the Exponent appendix. The Patriots balls were measured first (page 68), so they experienced substantially less of this effect.

Exactly, Hamobone1818!

I also hate that this is clearly a position piece by an attorney. He has a conclusion and uses the facts that only support that conclusion. There is no weighing of the facts here or presentation of facts. Its conclusion followed by the facts we uncovered that support that.

hambone1818 said:

That's what I don't get...they're basing conclusions on the fact that the Colts balls didn't drop as much as the Pats balls. Why is that relevant, doesn't it stand to reason that maybe the Colts balls didn't actually start at 13? That the Colts balls were inflated at a lower temp than the Pats balls?

I feel like I'm taking crazy pills...everyone's talking about devoid-of-context text messages between two asshat ballboys and ignoring BASIC SCIENCE.

Click to expand...

See the pages ~51 of the Exponent appendix. Both sets of balls were gradually gaining pressure from being inside in warmer air, but the Patriots balls were measured first. Therefore, the Colts balls experienced this effect much more than the Patriots balls. Additionally, it is possible that the balls were measured with different gauges at the beginning of the game.

It's a typical prosecuting attorney's report......

I really hope that there will be articles in the next few days by reputable scientists/engineers poking holes in the analysis provided by the Wells report.

Refs only measure 4 Colt footballs at halftime due to time constraints???????

WTF were they doing to the 12 Patriot footballs that took so long??

Biggs1221 said:

Page 198-99 of the report (page 39 Table 10 of the Exponent report). Am I reading this right that they agree that the expected drop in pressure from 70 degrees to 48 is 1.13 for a ball filled to 12.5.

and on page 7 of their report, Table 4, the average measured drops at halftime between the two testing officials was 1.39 and 1.01.

So, basically, the numbers were what should have been expected?

Click to expand...

Yup. And that's just considering temperature alone. Other factors, like rain temp cooler than air temp, condensation of water vapor, added flexibility of wet leather were not considered. The real anomaly here is the unnatural lack of pressure loss in the Colts footballs.

Biggs1221 said:

and on page 73 of the actual report, the pats balls, post game, that they inflated back to 12.5, were now at 13.5. So, they jumped up a whole psi?

Doesnt a lot of this not make sense?

It looks like the scientific evidence in the report is based on comparing what happened to the patriots balls compared to the colts balls.

Yet there is NO detailed analysis of differences in inflation temperature and sideline storage temp between the two sets of balls?

Click to expand...

That's just plain bias right there. Nothing objective or fair or anything that would pass muster for a real scientific paper.

Tony Cahncuhd said:

Yup. And that's just considering temperature alone. Other factors, like rain temp cooler than air temp, condensation of water vapor, added flexibility of wet leather were not considered. The real anomaly here is the unnatural lack of pressure loss in the Colts footballs.

Click to expand...

It's not necessarily unnatural lack of pressure loss as you say.

But rather a complete lack of recorded information and lack of complete testing. It is dumb that they assumed that all the Colts balls were 13.0 PSI when tested. It was also dumb that they only tested 4 Colts balls at halftime.

(Hint: Dumb is pretty much the them of this whole "investigation")

BlueThunder said:

Refs only measure 4 Colt footballs at halftime due to time constraints???????

WTF were they doing to the 12 Patriot footballs that took so long??

Click to expand...

Maybe they had to take a leak.

patsfan06 said:

It's not necessarily unnatural lack of pressure loss as you say.

But rather a complete lack to record information and lack of complete testing. It is dumb that they assumed that all the Colts balls where 13.0 PSI when tested. It was also dumb that they only tested 4 Colts balls at halftime.

(Hint: Dumb is pretty much the them of this whole "investigation)

Click to expand...

True. The quality and completeness of the data here is piss poor.

We're screwed....the problem is that Troy Vincent and Goody have 3th grade & comprehension reading levels.

The other thing that caught my eye is a complete lack of actual error analysis. You can't say anything about how accurate your findings are (and thus conclusion) if you don't have any error analysis to compare it to. What would have been a more scientific approach would have been to get errors on all the variables (possible starting pressures, temperature variations, weather effects, etc etc) and permeate the errors to get a an error on the expected PSI drop. That way you have something to compare the outliars to. As is, we don't know if 0.4 PSI off the expect drop is within a standard deviation or well beyond 5. They could have graphed the data and looked for outliars and seen how the data fit taking them out (which would suggest incorrect readings) Without proper error analysis, the conclusion holds no weight. It's a complete hack job, nothing passes peer review without error analysis and if it's not good enough to pass peer review it's not worth anything.

Not matter what complicated analysis you perform though, you simply won't come up with any conclusive because of all the assumptions here. Different gauges for readings, initial pressures given by memory, not knowing what gauges were used when, etc. The data is simply garbage. You can't make a meaningful conclusion with garbage.