The article deals with concrete and abstract methods of assessment of damages due to the creditor after the contract is terminated because of its breach by the debtor. The commentary is based on the detailed analysis of cases on compensation of damages in which arbitrazh courts have applied these methods of assessment. The focus is on the conditions for the application of these methods as they have been developed by the court practice, requirements to the parties’ behaviour, the content of the judgment based concept of reasonableness of the conditions of the replacement transaction (including its price), the burden and the method of proof. The article pays special attention to the new approach to these methods in the Ruling of the Plenum of the Supreme Court of the Russian Federation No. 7 of 24 March 2016 «On Application of Some Rules of the Civil Code of the Russian Federation on Liability for Breach of Obligations». In particular, the article demonstrates that the sphere of the application of the abstract method was widened significantly in accordance with the recommendations of the European civil law doctrine.