<p>Research on coal samples from the Kolchugino series in the Baidaevsk and Belovsk regions of the Kuznetsk Basin confirms that the degree of reduction of coal samples may be quantitatively estimated by reflectogram analysis and the clinkering and coking properties of coal samples with similar technical and petrographic characteristics may be assessed by the same method. This method was developed by VUKhIN specialists for the analysis of very similar coal samples (coal twins) and assessment of batch quality in coke production. It is effective and simple to use.</p>