JayMan
Footballguy
Very, verySo from what I get from this, is Cobalt, you don't really deny that strength of schedule effects the outcome of a player's FPs. I believe that you, along with anyone who has ever given the slightest thought on it, agree that a player will do better against weaker defenses that tougher ones.
But, what you are questioning is the ability to RATE a defense in the preseason? Is the correct? That using SOS might not have the effect we are looking for when drafting players because we really can't say which teams will have a weak defense and which will have a tough defense.
I'm drawing a thin line here, but I think it is a crucial point to your arguement that several people are missing. And I believe there is some validity. That is why post-season analysis supports SOS and pre-season analysis doesn't, and why we begin to see effects during the season. Mid-season and beyond, we know which defenses are good and which are bad. But pre-season just hasn't seen the accuracy for defenses as has been seen for position players. I think this is further backed by the usual advice on drafting defenses, late in the draft, because they are all pretty similar and hard to predict. But some want to tweak player by 10 to 15% because he faces a weak or tough schedule. There does seem to be a bit of inconsistentance in this two lines of thought.
It's not that SOS has no effect on a players season, its simple that we are unreliable at predicting how good a defense will be, and therefore, unreliable at predicting how 16 of the unreliable predictions will affect the offensive positions.

I have read all the posts in this thread - must be my Masters in Applied Maths and Statistics that makes it enjoyable!

I don't want to jump into the conversation Cobalt, Chase and Marvin are having - I was just wanting to make sure all those that are saying:
1. On a particular weekend - I'll go with the QB playing the Titans and not the one playing the Bears;
2. If everyting is equal in my mind between QB1 and QB2 - I'll look at SoS to make sure I take the one that has the easiest schedule;
are arguments that are not looking at the big picture here because: What Colbalt is trying to figure out is if postseasonSoS (i.e SoS based on last year's FP allowed by Defences) is statistically significant to predict this year's QB performance - not, which QB should fare well against that particular defence on weekend 6...
In fact, he wants to figure out if postseasonSoS is a better indicator than a coin flip to choose between QB1 or QB2 at the draft if everything else is equal in your mind... and he's not saying that postseasonSoS is not a good indicator - he's just stating that no one has proved statistically that it's significant...
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Allow me to draw a simple analogy between postseaonsSoS and FFDef rankings... We all know that in today's NFL many players change teams / new schemes are implemented / players were injuried in year n-1 that will play in year n / some guys played all games in n-1 but will only be able to help their defence in 6 games this year... all factors that make FFDef rankings (at the beginning of the year) difficult to predict. Just look at last year's rankings at the beginning of the year and the Ravens were the clear cut favorites - while the Bears were available on your WW... we all know it's unpredictable to a certain degree...
I think it's the same thing at hand here with postseasonSoS - for all the same factors... if you looked at Carson Palmer SoS at the beginning of last year you saw that he was going to play the Ravens twice and that would equate into a very tough SoS for him - and we all know the Ravens weren't up to the challenge last year...
Add to the fact that last year the Cards might have faced poorQBs all year long - thus having a good QB_FP allowed - thus making the postseasonSoS a tough one for the QBs playing the Cards this year... while in fact we know their QB_FP allowed from last year is flawed (this is where normalisation is required)...
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I think Marvin makes a valid point in saying that we should let a half-season go by - calculate the inseasonSoS for the last few week's and go from there... this is throwing out the window most of the "misleading factors" mentioned above - in my opinion... but this, is not helping us at the draft at the beginning of the season - and this is why numbers crunching is still at hand to see if postseasonSoS is statistically significant...
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All of this to say that I have not add anything to he discussion / nor show any statistical significance in favor or against postseasonSoS - only that the background / factors seems to make it unreliable or unpredictable at best...
My 2 cents