I and I wrote:
That half in Chicago three weeks before the marathon was the single biggest factor in her relatively mediocre WC run.
I disagree. Throwing up her fluids starting at 29k indicates she did not properly test her fueling strategy and tolerance in warm, slightly humid conditions. She ran almost perfectly even splits (something like +13 seconds positive), so if she could have kept fuel down, she would have very likely negative split like the rest of the top five, as the second half pace was well within her range based on the Chicago Half.
I think it would have been a more effective race preparation strategy to have sat on Chad Ware at the Chicago Half, and tried to outkick him in the last 2k, but at the end of the day, Kara going 30 seconds faster than she probably should have was not material to the outcome of the WC marathon.