I've been trying to create a general way of calculating an adjusted value for NHL statistics by taking into account the league average and the opponents estimated average.
It would basically work like this, say, for goals scored (G):
Code:
G_adjusted = G_Actual - (OppAllowed_G - LeagueAllowed_G)
where:
G_Actual = The actual number of goals scored in the game
OppAllowed_G = The average number of goals allowed by (scored against) the opponent that season
LeagueAllowed_G = The average number of goals allowed by (scored against) the entire league that season
This should take a statistic and adjust it so that it represents what the team would have scored if they were playing a league-average team instead of that opponent.
My question, is the equation above correct? Or should I convert the G_Actual and OppAllowed_G to z-scores using the mean and standard deviation of LeagueAllowed_G, then convert back to get an adjusted value?
Does anyone have a term for what I'm doing here? I assume it's been done before.
Thanks,
podonne