Kammala jumla mai zuwa: Böök ya taka leda da yawa daga cikin manyan 'yan wasan duniya, kuma yana da rikodin rikodi a kan Miguel Najdorf (+ 1 -0 = 2). Ya doke Max Euwe tare da baƙar fata a Dubrovnik a 1950, da kuma dan wasan chess na Estonia Paul Keres a cikin
1952 gasar Olympics ta Helsinki.