This paper reviews the anatomy of predictions for pile and pile group performance, and discusses the various facets of the prediction process. A series of case histories is presented in which successful predictions were made of the pile performance. Most of these cases involve a single pile or a small group of piles. A further series of case histories is then discussed in which the predictions were far less successful. Most of these cases involve larger pile groups. The reasons for the success or otherwise of the predictions are discussed, and it is concluded that successful predictions require a combination of good ground characterization, a sound theory which reflects the mechanisms of behavior, appropriate selection of the necessary geotechnical parameters, and a good knowledge of the applied loadings, together with a measure of good fortune
