Introduction I was curious to model the effectivness of Messi scoring goals in La Liga. He has been Pichichi for the last 3 years, so I guess he is quite effective in scoring goals in the opportunities he has. To model the goals scored by Messi in different seasons, I will use the following bayesian models: Simple model Hierarchical model State space model Simple Model I am going model the number of goals scored against the attempts during each season. Each parameter of the model, for each season, is going to be modeled independently. The models is very simple: \[\textrm{Likelihood: } \quad score_i \sim binomial(N_i, p_i)\] \[\textrm{Prior: } \quad p_i \sim beta(\alpha, \beta)\] where, \(score_i\) number of goals scored in season i \(N_i\) number of attempts in season i \(p_i\) proportion of goals scored against the total attempts in season i \(\alpha\) and \(\beta\) parameters of the beta distribution that I need to figure out Now, I need to figure out those \(\alpha\) and \(\beta\) parameters that model the proportion of goals. Read more