I've run CIM around 10 times between the '80's and '90's, along with quite a few other marathons. While it's a net downhill course, and point to point I wouldn't rank it any higher than Chicago on the speed scale (Compare '17, '18 CIM times vs same runners @ '19 Chicago). For those who have been around a while they can attest that conditions the past 3 years have been unusually awesome as compared to some previous versions. The course does have a 300? ft net drop, But there are plenty of rolling hills in the first half of the race. I'd bet that 1/3 of the net drop all occurs in the first 1300m of the race, before runners head up a 50ft climb to the mile mark. The past 2 years the race has been the US Championship event and they caught perfect conditions. This year Everyone who didn't have an OTQ had this earmarked as their attempt. It also helped a LOT that race organizers (Sacramento Running Association) provided 2-3 pacers for the women trying to run 2:44, and the men trying to run 2:18. As trials chasers ran by at 10k there was a massive group of men and women tucked in behind said pacers. Add another perfect weather day and you had another ridiculous number of OTQ's. With all of this being said, most Were wearing THE shoes.