I am a student writing is thesis, very unexperienced in R but I have to use it. My research is a stated preference survey based on a choice between a bike, or public transport commute. I have to use the mlogit funciton to fit a MNL, but I cant seem to figure it out.

I have a data set of 30 cases. The variable values change weekly but I need to compare two of the cases (teams) each week so for example, I might want to see the difference between case 1 and case 10, or case 2 and case 30 but these two case comparisons will also change each week (e.g., number of games played, etc.) Can I do this with instructions in R or do I have to change the set up of the data set. The place number and name are always the same.