Research shows that teachers' grading is influenced by non-achievement factors in addition to official criteria, such as knowledge and skills. Some grading criteria are internalised by the teacher, who is sometimes unable to verbalise the criteria used and refers to what is called a "gut feeling". Therefore, transparency, validity and reliability are problematic. The aim of this study was to explore which criteria physical education teachers consider important when grading. Such an exploration makes it possible to discuss how the verbalised criteria and the value they are given by the teachers can be understood. Four Year 9 teachers at different Swedish compulsory schools were interviewed using Kelly's Repertory Grid technique. Among the verbalised criteria, four themes were identified: motivation, knowledge and skills, self-confidence and interaction with others. The teachers sometimes had difficulties predicting which criteria had relevance to the grades given, and the criteria considered important by the teachers were not always reflected in the grade. The verbalised criteria revealed teachers using grades to encourage such student behaviours that helped them to handle the classroom situation and to facilitate students learning. To become cognisant of and develop their grading, methods to verbalise their individual grading criteria were needed, and Kelly's Repertory Grid technique is one possible option. The results provide discussion points about reasons for the way teachers are grading.