Task: Question Generation
Input (English): Background Paragraph: Negative-splitting is a racing strategy that involves completing the second half of a race faster than the first half. The racer runs slow in the beginning, and gradually runs faster as the race progresses. This is typically seen as a conservative racing strategy, but in distance events, many world records have been run with a slight negative split.[7]. 
Story: Michael and Robert, two high school sprinters, competed in the 800m sprint earlier today. Both were attempting to implement the negative split strategy, though with varying degrees of success. Both Michael and Robert competed the first 400m of the 800m sprint in 2 minutes, but Michael completed the last 400m in 1 minute and 30 seconds, while Robert completed the last 400m in 1 minute and 45 seconds.
Output (English): Which athlete had a larger negative split?