text: In the BGIT, we assumed that a CH always makes a constant contribution to ΔH° values for cyclic system. H° values for a number of structures and represents an average value that gives the best agreement with the range of experimental data. In contrast, the strain energy of cyclobutane is specific to the parent compound, with their new corrections, it is now possible to predict ΔH° values for strained ring system by first adding up all the basic group increments and then adding appropriate ring-strain correction values.
  The same as ring system, corrections have been made to other situations such as gauche alkane with a 0.8 kcal/mol correction and cis- alkene with a 1.0 kcal/mol correction.
  Also, the BGIT fails when conjugation and interactions between functional groups exist, such as intermolecular and intramolecular hydrogen bonding, which limits its accuracy and usage in some cases.