Dr Max Euwe
Euwe gave challange to Alekhine in 1935, Alekhine lost the 30-game match by a single point and Max Euwe, a total gentleman in all aspects., broke with all precedent by agreeing immediately to a return match. Euwe, an academic mathematician by profession, had won the title through his clarity of thought and exceptionally diligent preparation - he had crateload of books full of his opening analysis and it was impossible to gain any advantage against him in the early phase of the game. Euwe, is less popular, although, among the all world champions. Like another world champion of dissolved Soviet Union Tigren Petrosian. ChessWish.