• Memory for very long lists of digits is explained by skilled use of story mnemonic.
• The story mnemonic is assessed by verbal reports and validated by experiments.
• The story mnemonic generates unique retrieval cues to support serial recall.
• Memory for very long lists can be accounted for by Long-Term Working Memory.
• Assessment of a Guinness Book World Record winner’s exceptional memory.
In a recent paper, Hu, Ericsson, Yang, and Lu (2009) found that an ability to memorize very long lists of digits is not mediated by the same mechanisms as exceptional memory for rapidly presented lists, which has been the traditional focus of laboratory research. Chao Lu is the holder of the Guinness World Record for reciting the most decimal positions of pi, yet he lacks an exceptional memory span for digits. In the first part of this paper we analyzed the reliability and structure of his reported encodings for lists of 300 digits and his application of the story mnemonic. Next, his study and recall times for lists of digits were analyzed to test hypotheses about his detailed encoding processes, and cued-recall performance was used to assess the structure of his encodings. Three experiments were then designed to interfere with the uniqueness of Chao Lu’s story encodings, and evidence was found for his remarkable ability to adapt his encoding processes to reduce the interference. Finally, we show how his skills for encoding and recalling long lists can be accounted for within the theoretical framework of Ericsson and Kintsch’s (1995) Long-Term Working Memory.