Fitting flood prediction curves by eye to the data of return period plots is an intuitive approach to estimating n-year flood discharge magnitudes from single-site data. However, the subjective nature of this “procedure” means that it is unlikely to be adopted as a recognized flood estimation technique. An experiment with a group of volunteers demonstrates that some individuals are capable of subjectively fitting generalized extreme value curves to yield flood quantile estimates from simulated data with an accuracy comparable to probability weighted moments. This encourages the development of alternative formal flood estimation procedures based on some form of pattern recognition. Such procedures might mimic the more talented individuals' approach to curve fitting, without the disadvantage of subjectivity.