We report the thermodynamic stabilities and the intrinsic strengths of three‐center‐two‐electron B−B−B and B−Hb−B bonds (Hb
: bridging hydrogen), and two‐center‐two‐electron B−Ht bonds (Ht
: terminal hydrogen) which can be served as a new, effective tool to determine the decisive role of the intermediates of hydrogenation/dehydrogenation reactions of borohydride. The calculated heats of formation were obtained with the G4 composite method and the intrinsic strengths of B−B−B, B−Hb−B, and B−Ht bonds were derived from local stretching force constants obtained at the B3LYP‐D2/cc‐pVTZ level of theory for 21 boron‐hydrogen compounds, including 19 intermediates. The Quantum Theory of Atoms in Molecules (QTAIM) was used to deepen the inside into the nature of B−B−B, B−Hb−B, and B−Ht bonds. We found that all of the experimentally identified intermediates hindering the reversibility of the decomposition reactions are thermodynamically stable and possess strong B−B−B, B−Hb−B, and B−Ht bonds. This proves that thermodynamic data and intrinsic B−B−B, B−Hb−B, and B−Ht bond strengths form a new, effective tool to characterize new (potential) intermediates and to predict their role for the reversibility of the hydrogenation/dehydrogenation reactions.