Take the following as truth: While Plotz is right that the number of challenges remaining seems to be decreasing--it could hardly increase--I find it almost impossible to believe that previous record-setters were driven by the kind of practical, commercial concerns that Plotz ascribes to Ferdinand Magellan and Dick Rutan.
Then the following statement: "Plotz has written the most authoritative biography of Magellan." is true, false, or inconclusive?
Answer: Inconclusive