Weikl et al. have developed an approach for finding low-entopy loss routes of folding for two-state proteins based on the graph-theoretical concept of effective contact order (ECO) and using clustering of native contacts in contact map representation. Their model predicts that proteins fold by "zipping-up" in a sequence of small-loop-closure events, depending on the native chain fold. The folding pathways of proteins predicted agreed with experimental results, phi-value analysis as well as correlates with experimental folding rates for two-state proteins.

Reference: Weikl TR and Dill KA. (2003). Folding rates and low-entropy-loss routes of two-state proteins. J Mol Biol. Jun 6; 329(3):585-598.