Should I be trying to replicate the NEAS results?

[NEAS: This is an independent student project. The NEAS postings are suggestions to get you started. You can construct an ARIMA model, compare two or more models for a given era, compare two or three eras by type of model of by model parameters, examine seasonality, test out-of-sample forecasts, and many other items.]

Hi NEAS, I need help on my student project. I'm trying to do a time series on points scored per game for a player, and this player played different number of games per season. Now I see that there is seasonality in the scoring, but how do I unseasonalize? The Chapter 10 in the cryer chan text mentions seasonal models, Yt-Yt-12. But the games are not in order 12 or any order in fact (say he plays games 1,2,5,8,9,12... etc in one season, no matter what Yt-n is, I cannot remove seasonality with this method)

What other methods of unseasonalize are there?

[NEAS: Use only the games he played: if he plays 40 games in one season and scores 400 points and 80 games in another season and scores 600 points, his points per games are 10 and 7.5; for longer term cycles, one needs time series models with more lags.]