He ran the 10K in Prague. Have you ever HEARD of Prague being a high class meet? He was the only big name there, the pacemakers screwed it up for him early so he was left out in the cold for a lot longer than he should have been, and I also seem to remember that it was raining.
You toss in a few 66-67 second laps and he will subconsciously ease off knowing he's not going to get the record.
This is a guy who ran his last 500 in 1:10 last year and in 2003 also ran his 2nd 5K in 13:10, again easing off once Gebrselassie and Bekele ran away from him.
Again, Bekele ran a highly competitive 10K in a great meet, Hengelo, with Dinkessa clipping his heels the whole way.
Sihine ran in a bad meet in the rain with no competition and bad pacemaking. As for Sihine's PB, Dinkessa came from nowhere to run 26:30. So did Renato's runner Kemboi when he ran 26:30. I am certain in good conditions with good competition Sihine would destroy his PB and run close to or under the WR. It seems you didn't see his 26:39. He looked extremely relaxed just following Geb. It was another WR attempt that fell off due to bad pacemaking. MAny pacemakers simply cannot go very long at 63 per lap, so Sihine's best chance at getting the WR is in a race with Bekele, Dinkessa, or Gebremariam. He ran his last 100 in that race in 12 seconds. You're not running at maximal capacity if you can finish that fast.
Because he's training. He got the evaluation of his fitness he wanted, was disappointed, and has no need of more races because he can return to Ethiopia and get all the testing of his shape he needs following Bekele around the track at 8,000 feet.
Remember, these guys last year did a 7K time trial passing through 5K in 13:22! That's at 8,000 feet. Why would you need a European race to tell you you are in shape when you can do workouts like that. It's the same reason Bekele did not run Oslo and Rome even though he would probably have easily won the Million dollar Jackpot; Kostre wants those guys together making a strong push for Helsinki.
In 2003 he was not the same runner he is today. In 2003 his 5K PB was 13:06, so running the 26:58 and 27:01 that he did was remarkable for someone with that 5,000 time.
He crushed Bekele at the Ethiopian 5K running 13:35 to his 13:47. That makes him one of 3 athletes ever (Geneti and Chebii the other 2) to beat both Bekele and Gebrselassie.
In Athens, again, watch the race. Bekele took off and immediately opened a gap down the straight. Sihine saw he was not coming back and so ran in strongly but not all-out. Had he really chased Bekele strongly it would have been closer. You underestimate the guy. See what happens at Helsinki if he is healthy and fit.
There are very few athletes in the world who can, off 27 minute pace, take off and run 1:06 for the last 500. Sihine has a year more of training behind him and a better chance to respond to that tactic if Bekele uses it.
Because he can keep the same speed as Bekele without using his full range of motion. If Bekele runs at 61 per lap kicking himself in the back, eating up ground, and really using his full range of motion, it seems like he is nearly maxed out. Even if he gets faster there is not much more he can do with that stride. It's about as long and fast as it will get.
Sihine on the other hand has a more clipped, lesser stride that CAN be expanded with more training. He can open it up and get faster. Of course this is hypothetical, but it's merely an observation about potential. in absolute terms (# of seconds) I think Sihine can improve more than Bekele by a ways.
He said he's trying to beat him. He has once before and he's the next best these days at 10,000. If anyone can beat him, it's Sihine.