10-19-2021, 12:27 PM
(10-19-2021, 12:12 PM)fredtoast Wrote: None of this tells me anything.
What is EPA based on? How is it calculated?
What is CPOE based on? How is it calculated?
I realize that the most simplistic statistics often don't tell the complete story, For example a high completion percentage does not mean much if the QB never throws the ball more than 5 yards. But in order to appreciate these new metrics I have to have some idea of where they come from.
Say the Chiefs start with the ball first-and-10 from their own 25-yard line, where its expected points would be about 1.06. If Patrick Mahomes throws a 15-yard completion, making it first-and-10 on the KC 40-yard line, where the expected points is now 1.88, the EPA of that play would be 1.88 – 1.06 or 0.82. In other words, that completion increased the Chiefs’ expected points on that drive by just over three-fourths of a point. If instead of the completion, Mahomes was sacked for a 10-yard loss, making it second-and-20 from their own 15, the new expected points would be about -0.54 and the EPA for that play would be -0.54 – 1.06 or -1.6. This means the sack decreased the amount of points the Chiefs were expected to score on that drive by 1.6 points.
For CPOE, it is a little more simple though I don't know all of the formula. It is taking into account field type (dome or non-dome), depth of target, yards per attempt, sacks/hits and a few other things I believe. Once these are inserted into a formula, you have a predictive formula that will tell you what that QBs completion % is expected to be. Then you take the QBs real comp % and subtract it by the expected comp % which then gives you CPOE, or Completion Percentage Over Expected.
