Almost nobody does what you suggest and even doing this does not guarantee you will consistently improve. You don't know what you don't know, and masters are often not vocal about intricacies of their strategy. Many of them are geniuses, particularly in strategy type games, and as such people with much lower G factor probably have a slim chance of ever reaching that level. I know several of them myself. Gave them visual IQ tests like ravens progressive matrices. I know the validity is not very high but of the 6 people diamond 1 or higher in League of Legends I gave the test to, not a single one scored below 135.