You can go out in 1:51 and close in 26 if you have enough left in the tank that is but at the same time that is brutal gear shifting to pull that off in a 1000m. In college I ran 2:24 and typically went out in 1:53-1:55 in a 1000m and ran consistent 2:24-2:25 range on numerous occasions. A 1:50 for these guys is still no joke but is more than likely what a 1:55 was to me back in 06 so with this being said I agree 1:49-1:50 would mean this record is on anything slower would make the record attempts pretty doubtful. I have not read the entire post but would think a possible pace setter taking them through in the high 1:48 range would get the crowd going as well as there momentum up for the attempt. Anyone I am a big 1000m fan and wish the best of luck to both of these guys also love seeing a runner my age "Brannen" still running for records!!!