I don't change my opinion about the effects of EPO, also after the new of the ban of Kiptum. I'm sure that is possible to run at the WR pace for athletes completely clean, of course when there is the right talent, and the right training.
The general assumption that, if the number 3 in the world is doped, OF COURSE the other 2 athletes faster than him MUST be doped (because is not possible that a clean athlete can beat a doped athlete) is a total bullshit, because in that equation there are not the two most important variables : TALENT AND TRAINING.
People thinking in that way could be right only supposing that ALL THE ATHLETES could have the same talent, and that different training systems don't exist (so the training can produce, ALWAYS, the same final result).
But the talent is not the same, and who never had the opportunity to work with one EXTRA-TALENTED athlete can't also imagine what talent is. I saw Bolt winning World Junior Championships in 2002 when was not yest 16 years old, against sprinters 3 years older than him, and immediately said "this guy in the future will be the new WR holder of 200m and 400m (next year, in 2003, when 16 and half years old, he ran 400m in 45"35). And I think that the NORMAL gap in 200m between the best Bolt and the second best in the World had to be 6-7 meters, SO EVENTUALLY ARE THE OTHER ATHLETES UNDER 19"70 THAT HAVE TO DOPE FOR RUNNING SO CLOSE TO HIM.
The same with Shaheen. The first time I saw him in 1998 (he was 16 years old, and was in training in Iten followed by Joseph Ngure, at that time assistant coach of Brother Colm during the training camp organized for juniors in December, together with Cornelius Chirchir), I said "I hope in the future to have the opportunity to coach athletes like these two. With that talent, I see the possibility to run 3'25" (Cornelius) and 7'50" (steeple), and, when really I could coach Stephen Cherono (still junior), I was not happy of his final WR, because I know he could run under 7'50".
Sometimes there are athletes with something absolutely bigger than other competitors in the same events.
This was the case of Kenenisa Bekele, of Bolt, of Shaheen, of Edwin Moses, of Ashton Eaton, of Zelezny, of Jonathan Edwards, of Yelena Isinbayeva, and of Eliud Kipchoge. All these athletes assemble together big physiological, morphological and biomechanical talent, with incredible mental ability, in terms of continuity, concentration, courage, motivation, and application.
Second factor : TRAINING.
I saw several times in my life big changes, in short time, with athletes already coming from mani years of career, after changing their training, increasing volume and quality of their workouts. Not always a sudden improvement, after years of similar performances at lower level, means doping. We need to know the history of their life before giving any opinion about the athletes. How many times somebody had years of not professional training (having, for example, a full-time job), and, when finally had the opportunity to chose a professional road in athletics, started to train very much more and better, improving everything around the athletic activity, such as rest, recovery, physical assistance with massages and therapies, etc... ?
In Kenya, how many times we met runners (already 30 years old) who worked as farmers in their village, running only 4 times per week, competing in small local races, with problems to eat twice per day because the lack of money, but able running a full marathon in 2:17 - 2:20 in those conditions, who, finally joining a camp where possible to train with a strong group, and to eat twice per day, in 1 year of training were able to move to 2:07 or better without any problem ?
Kiptum belongs to that category. He started his official activity already 27 years old, running a lot of local competition in Kenya, and winning almost every time. With very little training, in 2015 he ran his first marathon in Rabat arriving 3rd in 2:11:36. Next year he had a good HM in Copenhagen running 59'36".
Everybody in Rift Valley knew his great talent, and in my opinion, especially after running the marathon in 2:05:26 in Amsterdam in 2017, he was already one of the group of athletes able to run around 58'30".
What can give me some doubt is that last year, in Copenhagen (16.09), he lost the race by one my athlete (Daniel Kipchumba), running only 59'09", without showing particular shape. However, the WR in Valencia was about 40 days later, and athletes of big talent in 40 days can change very quickly their shape.
What I can say, about the training in altitude, is that it's not possible to justify fluctuations, in the BP, if ALL the OOC tests are in altitude. We can see some difference about the level of Hb and Hct between some test in altitude and at sea level, due to these two different situations ; but never we can see fluctuations if the test are in the same situation (always at sea level, or always in altitude). In the case of Kiptum, all his OOC tests were in altitude, and if there is some fluctuation, this is probably due to the assumption of some medicine.