Ritz in one season was able to run 12:56, 27:22, and 60:00 while staying healthy. He has trained for and ran many marathons now and none of them has showed any promise of him being able to be a top marathoner. the guy could be one of a few athletes in the olympics with a sub 27:00 10k PR and those are the only guys that win medals. Or he could train for the marathon and not have a chance to win because you will need to run 2:04 at London and he will end up prob 10th place or higher. Also it seems like he can't stay healthy on marathon training so the lower volume with higher intensity stuff may be better suited for him.
Why is he so blind to see that he is a competitor over 10k on the track?
If he focuses on track for the next two years he will be one of the contenders for a medal and he will be the AR holder for 10k with a sub 26:50 time. I think currently his max distance is the half marathon. Similar to Zersenay Tadese who has failed at his attempts at the marathon so far.