Rating players before 1950 is really complicated because there are very few videos and sources. To do this I based myself on all the reports I could find: newspapers of the time, books, magazines etc . If ten out of ten sources tell me that player X is the fastest player in the league, then I will give him a proper value. In general, where it is not possible to give ratings I have given 'standard' values. Let me reiterate: the values I have given are PURELY indicative.