FanPost

Why the Nick Foles Trade is a Win for the Rams

Tim Heitman-USA TODAY Sports

This paper looks at the trade between the Rams and Eagles that saw Nick Foles trade his wings for horns. Personally, I think that this trade will be good for the Rams despite my personal feelings about Sam Bradford and his talent level. Before I begin, however, I have two disclaimers.

The first is that I am not a football wiz. I do not know as much about evaluating talent as a pro scout or 3K, nor do I claim to. I am just a College Senior studying Economics and Finance with a minor in Math and am going to approach my argument with a statistical analysis.

Which brings me to disclaimer 2: I will not be using the advanced mathematical models that are very popular today. I will make no use of on-field statistics or even PFF grades, even though I personally think they are very good. I will simply be using two of statistics simplest calculations, expected value and variance, to argue that Nick Foles upgrades the Rams expected talent level on the field and gives the Rams a better chance to win.

My first argument makes use of the traditional expected value formula that can be found in any stats book you will find, E(T) = the summation of p(T)*T, sorry for writing the summation but I do not know how to integrate mathematical symbols into a fan post. In my equation, T stands for the talent level a player has, p(T) is the probability of a particular player being able to play and E(T) is the expected talent level on the field - p(T) is at the heart of my argument.

Since 2010, Sam Bradford has been oft-injured - playing in 49 games out of a possible 80. This means that his probability of playing is about 61%. Nick Foles did suffer an injury this past season, but I have no reason to expect his broken collarbone will become a chronic condition like Sam's ACL. Therefore, I will put Nick Foles' probability of playing any particular game much closer to 100%, conservatively, I am going to place it at 95%.

Based on these probabilities of playing, E(TB) = .61*TB+.39*0 and E(TF) = .95*TF+.05*0, where TB stands for Bradford's Talent level and TF stands for Foles' Talent level (the .39*0 and .05*0 terms come from the fact they will add zero talent to the field if they are not playing). If we set these sets of equations equal to each other and solve for TB, we get E(TB) = 1.55*E(TF). This means that for Bradford to give the Rams a higher expected talent level, he would have to be more than 55% better than Nick Foles. You can look up their respective PFF grades and use those synonymously for their individual talent levels. If you do, I am sure Bradford is not graded 55% higher than Nick Foles. This means that Nick Foles will give the Rams the better expected talent level, which should lead to a higher probability of winning football games.

Further, using these same probabilities, p(TB)=.61 and p(TF)=.95, we can conclude the variability in the probability that each player will see the field. Fisher lives and breathes continuity as if he invented the term. Therefore, it is easy to conclude that he would like a player that is more consistently seeing the field. The formula for the variance of a proportion is VAR(T) = p(T)*(1-p(T)), also found in any statistics text book.

Using these equations, VAR(TB) = .24 and VAR(TF) = .05. Therefore, we can see that Sam Bradford is a much more inconsistent player in terms of health and playability than Foles. Yet again, I am not a talent scout or have intimate knowledge of how to run professional offense. However, I would think that it is obvious that at any position, being able to consistently start games is a bonus and helps the chemistry of the team as well as the talent level on the field. Therefore, in this respect also, Nick Foles is a better option at QB for the St. Louis Rams than is Sam Bradford.

Based upon both metrics, this trade gives the Rams a better option at QB than they had by upgrading the expected talent level on the field and by reducing the variability of who is playing at the QB position.