some reasons wrote:
1) Rupp was not in very good form for Boston 2017, while he is apparently in the best shape of his life for Boston 2018. There are few that could beat even Chicago 2017 Rupp. People downplay that performance because of the slow time, but that last 10km was ridiculous.
2) Kirui has had 1 race since worlds in August -- a 60:04 half. A good time, but he placed 6th, with the winner in 59:46. On the other hand, Rupp ran 59:47 in Rome into a headwind a month ago, with the last 5km solo.
3) It's a bit strange that Kirui hasn't raced in 2018, possibly indicating a training disruption/injury. At the least, his fitness coming into this race is unknown.
4) Rupp seems to do particularly well in poor weather and is accustomed to rain. Not sure about Kirui in particular, but East Africans tend to struggle with the rain/cold.
This is a great post--I didn't realize Kirui hasn't raced at all this year.
I'm definitely not trying to say we shouldn't call it "Rupp vs. Kirui 2.0" or argue that Rupp is the favorite. But the 1. Rupp 2. Tola 3. Berhanu predictions have befuddled me a little bit. I still don't think that Kirui is getting enough attention, but if he hasn't raced this year, it's hard to predict what he'll do.