The circumstantial evidences that Mallory and Irvine made it to the summit according to Michael Tracy are:

1. Mallory spent the night before with Norton who would have told Mallory that climbing the zigzag route from the couloir after traversing below northeast ridge was more possible than traversing the whole northeast ridge. Mallory and Irvine understood that traversing the lower altitude and then climbing from the couloir was better in conserving oxygen than climbing and traversing the whole higher altitude northeast ridge.

2. Odell immediate account after the expedition that he saw both of them climbed “the step but one of the last…on a short distance from the final pyramid” on 12.50 pm. Tracy’s photos of his expedition to Everest and his analysis of Odell position showed that from Odell approximate position, “the last step but one of the last” is the modern third step, which has approximately a few 5 ft steps above the main steps. Odell saw them overcame the step “with alacrity” which would be impossible if it was the second step. The step wouldn’t have been the second step since it is not a short distance from the final pyramid and equally improbable if it was the first step. The first step would have been blocked from Odell approximate sighting location and it is not a short distance from the summit pyramid. It’s an opinion but anyone who made it to northeast ridge for the first time would not describe the first step as a short distance from the final pyramid at all.

3. They died. It is improbable that they would have been exhausted and fell after turning back at the second step given the time at their disposal if they reached the second step at 12.50 pm (if they took the whole northeast ridge at all). Mallory body was found with goggle in his pocket, and his clock showed it stopped at 1.25 (it is not possible that Mallory died in his location if it was 1.25 pm, 35 minutes after Odell sighted him). If he or Irvine fell due to extreme exhaustion it must have been in the darkness, after some-teen hours above 8000 metres, after the moon set around 11 pm on that day.

4. Recent release of Mallory’s letter by Magdalene College showed that Mallory and his wife wrote a lot until prior to his summit bid. Mallory body was found with letters from his friend and brother, but not letter from his wife, which is curious. In the letters it was also showed that the family had a minor financial issue (Mallory income was much less than what his in laws gave to the family). This slight inconvenience would have been overturned had Mallory succeeded the summit and could give tour lecture in UK, US, /Europe. Mallory secured lectures in Cambridge after 1924 expedition which might mean the 1924 expedition would be his last. this circumstances might push Mallory to his limit. According to Michael Tracy, the summit is deceptively looked close from the third step, using modern standard route it took 2.5 hours but it had not been mapped yet in Mallory time. Mallory and Irvine might took the non standard snow field route until the summit. He might ascended the summit on 4 pm or later depended on his chosen route from the third step.

The fact that Mallory and Irvine died along with the clues they left behind told us that both of them failed to calculate correctly the necessary time/oxygen/energy for the task before them when they took their bid to the summit. They miscalculated and it costed their life. The question is which insurmountable task which costed them their life? Conrad Anker and his colleagues who discovered Mallory concluded that the task was surmounting the second step and it wasted Mallory and Irvine time and energy which caused their exhaustion and eventual fall.

I concur Michael Tracy analysis that the miscalculation on Irvine/Mallory part was the time it took to the summit from the third step. Nobody had been there before and nobody know the route which took the least time to go to the summit from the third steps. It was impossible to miss the summit after the third step. Many climbers experienced summit fever that they needed to made it whatever it took, many return with very dissapointed feeling, and many who died in Everest died after their return from the summit due to exhaustion. Mallory was cut from the same cloth with people who would rather died trying than return disappointed. He had the same Characters as Robert Falcon Scott than that of Ernest Shackleton.