New sub-OPR Calculations

[Ed Law]

Originally Posted by Basel A

It seems like this post explains what you did pretty well (at least for anyone who understands the base OPR calculations). Or were there any other twists?

Yes, that is how I did it. I didn't like scaling the score b based on number of matches. It has no mathematical basis. What I proposed to do was just an intuition. It seems more logical but I did not do the math at that time. I finally did the math and what I propsoed was the best way to do it.

However, as Kevin pointed out, it created weird numbers in some rare situations. It happens when teams have negative sub-OPR numbers and especially when teams were involved in surrogate matches or noshow or DQ matches. The reason is I scaled each of the sub-OPR numbers to match the overall OPR number.

I published a new set of data. Instead of scaling, I shift each sub-OPR numbers proportional to the absolute value of the sub-OPR number of the difference that needs to be made up. It works really well. If all sub-OPR numbers are positive, it gives the same number as by simple scaling.

I don't have time right now to explain in more detail. I will try to do that this weekend. I only spotcheck some events. If somebody finds something weird, please let me know.