The data used for the analysis in this research was gathered from the following two sources:

The first source is the transfer data, which includes things like the league, clubs involved, and transfer fee. The second source is player statistics. Combining these two data sets allows us to explore the relationship between game statistics and productivity with transfer fee.

In any data analysis research, data collection proves to be one of the most difficult challenges. Indeed, the lack of freely available data like this that spans many years and many leagues cause the data set for our analysis to be extremely small. This was a challenge for both creating an accurate model and analyzing trends in the transfer market.