With the occasional exception, non-small cell lung cancer (NSCLC) is not curable without some form of surgical resection. The good news—ie, the benefit—is that when appropriate oncological standards are followed, cure can be obtained in a substantial majority of operated patients. However, this benefit is not gained without exposing the patient to risk. This risk/benefit relationship is the yin and yang—the two opposing considerations—of thoracic surgery. The proximate risks associated with lung resection are morbidity and perioperative mortality. The challenge, both for a given individual and for large populations, is to maximise the likelihood of benefit while minimising the risk. The paper by Strand et al1 in this issue of Thorax (see page 991) addresses the issue of operative risk with regard to 30-day postoperative mortality. This paper makes a major contribution to this issue by clearly defining specific risk factors and even developing a helpful model to …