The Nobel-winning physicist Niels Bohr famously said that "prediction is very difficult, especially if it's about the future." Nevertheless, the prediction of rapid clinical deterioration has acquired its place in Acute Medicine. Time-urgent medical emergencies can benefit significantly from early detection when treatment delays increase the risk of death. Many Early Warning Systems (EWS) have thus been developed to stratify those at high risk of deterioration. It has been demonstrated that different types of EWS, including the Modified Early Warning Score (MEWS), National Early Warning Score (NEWS), and NEWS2, are clinically useful when identifying rapid deterioration. However, as we are inundated with risk stratification tools, it can be hard to decide which we should or should not use.