I'm new to statistics.
What type of model should be used to predict a basketball team's winning percentage? I am currently using a multiple linear model, but the residual vs. predicted plot shows my data points clustered in a circle. I standardized my explanatory variables since they were either percentages or totals.
Also, what model should be used for the Pythagorean Expectation formula? I would like to see what that would look like in R.