• The predictability approach. This paradigm was due to Claus P. Schnorr and uses a slightly different definition of constructive martingales than martingales used in traditional probability theory.[11] Schnorr showed how the existence of a selective betting strategy implied the existence of a selection rule for a biased sub-sequence. If one only requires a recursive martingale to succeed on a sequence instead of constructively succeeds on a sequence, then one gets the recursively randomness concepts. Yongge Wang showed[12][13] that recursively randomness concept is different from Schnorr's randomness concepts.