At 11:00am, local time, Marathon for women will start.  The course is very different from the classic London Marathon : here the athletes have to run 4 laps of a course with 26 turns per lap.
This means it’s not possible to use high speed, but the most important quality is agility in order to change pace very frequently.
The course seems to be perfect for athletes small size, with very high frequency in their running action.
This is one of the main qualities of MARY KEITANY, that in my opinion has 40% of chances for becoming the new Olympic Champion.
Coached in Iten by the Italian Gabriele Nicola, Mary could have a good period of training, in spite of the heavy rain disturbing the athletes during the last month.
The Kenyan Marathon Responsible, David Letting, was able to coordinate the programs of all the athletes, without changing their training, involving the personal coaches in the preparation.  This fact created a very good and relaxed atmosphere in the Team, and, also if the athletes didn’t train together, it was possible to have technical and tactical discussions between the coaches of the athletes (Gilbert Koech, husband, for Edna Kiplagat, and the husband of Prisca Jeptoo).
After London Marathon, it was very difficult to reach the same shape again.  I think Kenyan athletes are at 95% of the shape they had in April, but this is the same situation of the Ethiopian TIKI GELANA, winner in Rotterdam in very bad conditions (very strong wind) with an amazing 2:18:58.
The main rivals of the Kenyan women are the Ethiopians.  Personally, I don’t think ASELEFECH MERGIA and MARE DIBABA can have their best shape, since all the Ethiopians were obliged to stay always in the National camp for training with the National coaches, using different programs from the personal coaches of the athletes (Gemedu Degefu for Mergia, Getaneh for Tiki Gelana and Hajji for Mare Dibaba).  In my opinion, this behavior always goes to produce bad results, and personally I don’t think the situation can be very much different this time.
But the real danger, for all the Kenyan women, comes from the Russian LILIYA SHOBUKHOVA.  Already 35 years old, Liliya has a PB of 2:18:20 winning last year Chicago, in a way  similar what Mary Keitany was able to do in London this year.  She used a negative split (1:09:25 + 1:08:55) with the last 2.195m in 6:51, but the real difficulty was to do it with a temperature raising from 17° to 28°, and humidity becoming every minute more high.
Shobukhova, winners of the jackpot (500.000 USD) in the last two years, decided to skip the Marathon in Spring for preparing OG only.  This strategic choice can become the winning weapon in the case the shape of Mary is not at the right level.
Apart Africans and Shobukhova, I wait some good performance from the US athletes, specifically from SHALANE FLANAGAN, winning US Trials in 2:25:38.  This time is far from the PB of Kenyans, Ethiopians and Shobukhova, but I think she can run very close 2:20:00 and, in case of a first Half not very fast (without pacers, I think the speed can be no faster than 1:11:00 after Half Marathon), she can use her speed (she won bronze medal  (10000m) in OG 2008, and again in World Cross Championships 2011) for trying to win a medal.
Good competition can come from Japaneses (YOSHIMI OZAKI and RISA SHIGETOMO) and Italians (VALERIA STRANEO, ANNA INCERTI e ROSALBA CONSOLE), while Chineses are a mystery, but have the possibility to run very fast.
I think the first half can’t be very fast (I suppose between 1:11:00 and 1:12:00).  After this, Mary Keitany has to take the responsibility of the race in her hands, may be helped by EDNA KIPLAGAT, that can run very fast (she went under 2:20:00 in London Marathon) and is able to manage the pressure in top competitions (she won New York in 2010 and World Championships in 2011).  Shobukhova can follow, and at the end the race becomes a fact between these two athletes, with a clear plan : Mary increasing constantly the speed for creating a gap with Shobukhova, and this one only concentrated to stay with Mary till last 2 km.
My percentages  for Gold medal  :  50% Mary Keitany, 40% Lilya Shobukhova, 10% distributed between Edna Kiplagat and Tiki Gelana.  For bronze medal, some chances for Shalane Flanagan and another Ethiopian, if one of the above named athletes has to drop out, looking not possible to achieve the prevented medal-