Protein folding, tagged as a grand challenge/NP hard problem, has been an open area of research in diverse fields. Exploring folding from the configurational volume perspective in terms of phi (phi), psi(psi) backbone dihedral angles, we asked ourselves a fundamental question as to when do the neighborhood effects on the allowed phi, psi values of each residue take over to assure convergence of proteins to their observed unique tertiary structures. A mapping of the higher order steric correlations beyond Ramachandran plots from similar to 43612 protein structures comprising similar to 26.5 million amino acid residues reveals that conformational restrictions on allowed phi, psi values of each amino acid residue due to the N and C terminal neighbors - essentially a consideration of the sterically allowed regions of a tripeptide - ensure convergence of the configurational volume. (C) 2016 Elsevier Inc. All rights reserved.