# Filed under Primer …

## Historic team ratings – Chelsea

I’m going to push out a whole group of these in the near future so I figured it was worth a background post that I can link back to in order to explain future plots. In short, I regressed the shots, % of shots on target, and PDO of each Premiership team from the past … Continue reading

## A primer: qualcompTSR

This is something I’ve been playing with for a while, but I don’t have the patience to go back and check whether it’s actually more useful than TSR, and it takes an extra step to calculate, so I’ve yet to use it publicly. The concept is simple, and somewhat similar to 11tegen11’s relative shot rate … Continue reading

## A primer: Quality of competition (QualComp)

This is a pretty simple concept but I’ll be referring to it a few times so it’s worth a post. Quality of competition (QualComp) is used to give an indication of the strength of a teams opponents. I’ve already shown that a teams shots on target ratio (SOTR) is the most repeatable (and therefore reliable) … Continue reading

## A primer: Calculating regression to the mean

Recently I explained the basics of regression to the mean and why I’m going to apply it to football. I want to briefly expand on it by explaining how it’s size is determined for a particular parameter. It’s pretty simple to calculate and I’ll use the example of team points in consecutive years. The first … Continue reading

## A primer: PDO

Statistics in ice hockey tend to have names with no explanation as to their meaning. Developed by the online community the tradition is to name a stat after the person that developed them, hence PDO. That link and this one outline it’s use in hockey, and I’m interested in whether it applies to football as … Continue reading

## A primer: regression to the mean

Imagine you take a fair coin (one with equal chance of getting heads or tails) and flip it ten times. The average (mean) result would be to flip five heads (as the coin is fair) but you find that you actually only flip two. You then repeat the experiment and get four heads. The mean … Continue reading