Text: 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.
Entailment: Plot highlights that Magellan was driven by commercial concerns.
Contradiction: Plotz hasn't made any observations about Magellan's motives.