Did Irvine and Mallory make it? 

The Brits would love one of their own to be the first to summit Everest so every year they keep the fantasy alive.

Using text analysis of the description of Odell’s sighting of Mallory and Irvine, what is agreed in leaving time from Camp IV and what most experts say normal ‘travel’ time is up to Everest from the northern side, we can work out a probability and feasibility of whether it was even possible to summit.

Whether they did it all hinges on one thing – where they were, when Odell saw them, and this unravels the tale.

The reason for this is because there is an amount of time needed to get down safely before night fall. Most climbers do not want to die and will turn around when descent becomes peril. Serious cut offs to turn around where summiting is still uncertain, would have been between 3pm and 4pm.

It is also generally agreed Mallory and Irvine left Camp IV, as was the custom, at around 08.30. Mallory also stated he felt having oxygen allowed a late start.

So we can anchor analysis of ‘where they were’ in these factors for the feasibility they were in the right position (after the Crux of the second step) was 1 in 10 and making the likely probability of successfully submitting between 1 & 2%.

It is hard not to condole that not only did Irvine and Mallory not make it down, they didn’t make it to the top either.

GPT do your thing. 

Odell’s quote “At 12.50, just after I had emerged in a state of jubilation at finding the first definite fossils on Everest, there was a sudden clearing of the atmosphere, and the entire summit ridge and final peak of Everest were unveiled. My eyes became fixed on one tiny black spot, silhouetted on a small snow crest beneath a rock step in the ridge, and the black spot moved. Another black spot became apparent, and moved up the snow to join the other on the crest. The first then approached the crest rock step, and shortly emerged at the top. The second did likewise. Then the whole fascinating vision vanished, enveloped in cloud once more. There was but one explanation. It was Mallory and his companion, moving, as I could see even at that great distance, with considerable alacrity, realizing doubtless that they had none too many hours of daylight to reach the summit from their present position and return to Camp VI by nightfall. The place on the ridge mentioned is a prominent rock step, at a very short distance from the base of the final pyramid, and it was remarkable that they were so late in reaching this place.“

Mallory & Irvine, 1924: Odell’s Sighting, Timing, Feasibility, and the Probability of a Summit

INTRODUCTION

The question of whether George Mallory and Andrew Irvine reached the summit of Mount Everest on 8 June 1924 persists not because of sentiment, but because a narrow set of ambiguous facts admits multiple internally coherent interpretations. At the center of the debate lies a single observation: Noel Odell’s brief sighting of the climbers at approximately 12:50 p.m. on the Northeast Ridge. When combined with constraints of time, terrain, oxygen technology, and daylight, that observation becomes the hinge on which all summit probabilities turn.

This paper reconstructs the event using conservative assumptions and explicit penalties. It does not aim to prove or disprove a summit, but to bound its probability by examining what must have been true for Mallory and Irvine to succeed, given what is most likely to have occurred.

Odell’s OBSERVATION: WHAT WAS ACTUALLY SEEN

Odell reported seeing two climbers, moving upward together, on a rock step, near what appeared to be the base of the final pyramid. The sighting lasted only a few minutes before cloud closed in. Crucially, Odell did not describe one climber stationary, belaying, or engaged in obvious technical difficulty. His account is observational rather than interpretive; it reflects motion, not struggle.

When mapped onto the Northeast Ridge, this description aligns naturally with inclined scrambling terrain—particularly the First Step or the ridge immediately above it—where two climbers can advance simultaneously. It aligns far less well with the Second Step headwall, which enforces serial movement and prolonged pauses. Later reinterpretations that associate Odell’s words directly with the Second Step reflect retrospective mapping onto a later-understood route, not necessarily what Odell perceived in 1924.

THE DEPARTURE TIME: A FIXED ANCHOR

The most widely supported conclusion, based on Odell’s movements, camp routine, and period practice, is that Mallory and Irvine left Camp VI at approximately 08:30 a.m., with a plausible range of 08:00 to 09:00. Pre-dawn starts were not standard practice in 1924, particularly given Mallory’s belief that oxygen would permit later, daylight travel.

This departure time is critical. It fixes the temporal budget available before Odell’s sighting and constrains how high the climbers could plausibly have been by 12:50 p.m.

FEASIBILITY OF LOCATION AT 12:50

From an 08:30 start to 12:50 allows roughly 4 hours and 20 minutes of climbing at extreme altitude over mixed terrain. Using conservative pacing assumptions, three locations emerge as plausible candidates for their position at Odell’s sighting, each with an associated feasibility.

First, the First Step or its immediate approach zone is the most plausible location. This includes inclined ridge terrain and the lower slabs of the First Step itself. Given known reconstructions, this carries a midpoint feasibility of approximately 65 percent.

Second, the Second Step with the headwall still ahead is less likely but possible, with a midpoint feasibility of around 25 percent. This requires unusually efficient progress through the Yellow Band but does not yet demand completion of the crux.

Third, being already past the Second Step headwall by 12:50 is the least feasible scenario, with a midpoint probability near 10 percent. This requires both climbers to have completed the crux unusually quickly after an 08:30 start.

THE SECOND STEP AS THE DOMINANT CONSTRAINT

The Second Step headwall dominates all summit models. It is short but steep, technically exacting, and requires lead-and-follow movement. Clearing it consumes time disproportionate to its height, and downclimbing it late in the day dramatically increases fatal risk.

Any model that places Mallory and Irvine past the headwall by 12:50 must therefore overcome a strong feasibility penalty, regardless of how favorable the subsequent terrain may be.

DAYLIGHT AND DESCENT PENALTIES

Summiting Everest is not merely reaching the highest point; it requires surviving the descent. On 8 June, sunset occurred shortly before 19:00, with civil twilight ending around 19:20. Descending the Second Step headwall in darkness is an extreme escalation of risk.

Models implying summit times after approximately 18:00 therefore incur severe penalties, as they almost guarantee technical downclimbing in darkness.

SCENARIO ANALYSIS

First Step Interpretation:
If Odell saw Mallory and Irvine at or near the First Step, a summit remains theoretically possible but would likely occur late in the evening. The descent would almost certainly involve the Second Step in darkness. Despite being the best fit to Odell’s wording and the most feasible location, this scenario carries a summit probability of approximately 1–2 percent once descent risk is applied.

Second Step, Crux Ahead:
If Odell saw them at the Second Step but below the headwall, the crux still lay ahead after 12:50. Summit timing tightens further, and descent risk remains severe. This scenario fits Odell’s wording poorly and yields a summit probability near 1 percent.

Second Step, Past the Crux:
If Odell saw them moving on easier terrain after clearing the headwall, this is the only scenario that naturally supports a daylight descent. However, it is also the least feasible location by 12:50 given an 08:30 start. Once feasibility and daylight penalties are combined, this scenario yields a summit probability of approximately 3–5 percent.

EFFECT OF EARLIER START TIMES

Had Mallory and Irvine departed Camp VI one to two hours earlier, the feasibility of being past the Second Step by 12:50 would rise sharply, and daylight penalties would ease. Under such assumptions, summit probabilities could plausibly rise into the 10–20 percent range. However, these starts are weakly supported by historical evidence and therefore remain speculative.

CONCLUSION

All probability estimates converge on a single decisive question: where were Mallory and Irvine at 12:50 p.m.? If they were at the First Step, a summit is possible but highly unlikely. If they were below the Second Step headwall, it is vanishingly unlikely. If they were already past the headwall, a summit is plausible—but only because that scenario preserves daylight for descent, and only at the cost of low feasibility.

Accepting the most defensible departure time of approximately 08:30 a.m., the overall probability that Mallory and Irvine summited Everest on 8 June 1924 remains low and tightly bounded, most reasonably in the low single-digit percentages. The enduring mystery lies not in a lack of data, but in how finely balanced the remaining interpretations are.

Feasibility of Location at 12:50 p.m. (Given ~08:30 Start)

Location	Terrain Description	Midpoint Feasibility	Feasibility Range
First Step / approach zone	Inclined ridge or lower First Step slabs; two climbers can move together	0.65	0.50–0.80
Second Step (crux ahead)	At Second Step but headwall not yet climbed	0.25	0.15–0.40
Second Step (past crux)	Both climbers above headwall on easier ridge	0.10	0.05–0.20