“In a single instant of time, pure performance is all that matters, but, over a prolonged period of time, survival overcomes pure performance.” (Cf. Luca Delanna)
Playing Russian Roulette
Many years ago, I was working as a young research engineer in the steel industry. We were simulating heat transfers in the steel blast furnaces and in slabs during their heating in ovens.
One of my colleagues had a magnificent mustache. One night, we were testing our model on site. That was exciting but also awfully warm. When we went back to the hotel, taking our helmets off, we found out that his mustache had disappeared. The hairs had been burnt by the heat of the furnace.
Our team has been invited a few days later to dine at the home of our HR VP. At the end of the dinner, our host took out a revolver and a 9mm bullet. He put the bullet in the barrel, spun that barrel, and (I still wonder why) asked me to play Russian Roulette. Everyone was starring at me. After a few seconds of hesitation, I fired to the ceiling. Fortunately (for the ceiling and the well-set table beneath it), nothing happened. Yet everyone (except me) laughed like crazy .
This taught me two lessons.
The first lesson is that I had to be very careful with (some) HR VPs and with any kind of social pressure.
The second and most important lesson concerns a barbaric term: ergodicity.
Conflating Ensemble and Time Probability
What is ergodicity? Let me start with an illustration.
If you play Russian Roulette only once, the odds that you die are 1/6 or around 16%.
This is also true at the (large) ensemble level. If, say, 1000 people play Russian Roulette once each, the average death rate of this ensemble of people should be around 16%. The more people in the ensemble, the closer the death rate will be to 16%. This is the Law of Large Numbers.
But consider now the probability over time to die or survive Russian Roulette.
If you play several times, your odds of survival are (1/6)^n. 1/6 are your chances of dying with one round. And n is the number of rounds played. Useless to say that after a few rounds, your odds to survive decrease rapidly to 0. Over time, your probability to die is 1.
This implies that the average odds to die of an ensemble playing Russian Roulette are not similar to the odds of a single person playing Russian Roulette several times (in a row or not). This situation is said to be non-ergodic.
Conversely, in an ergodic situation, the average outcome of the group is the same as the average outcome of the individual over time.
A family with two working parents and two young children is an illustration of ergodicity. In this situation, the average family wealth is identical to its average wealth over time. A gas may be another illustration if we consider the individual states of the gas molecules to the temperature of the gas as a whole and its time evolution.
The key takeaway is that, in a non-ergodic situation, you should not conflate ensemble probabilities and time probabilities. Above all, avoid situation which can ruin you.
Survival Overcomes Pure Performance
What does it mean in your life?
When I was young, I believed that success came with the performance.
That meant skiing as fast as possible, sailing even when weather forecasts were not favorable, working very long hours…
Later, I understood that pure performance was indeed important, yet insufficient. Performance only made sense when related to others. So, belonging to a community of friends, working with a group of colleagues, or delivering a service making people happy became as important as mere performance…
Finally, later, observing the many lives of individuals I used to admire, I noticed how game-overs are common. Entrepreneurs get bankrupt. Successful leaders disappear miserably in the night of oblivion. Top athletes die in accidents while practicing their sport. Hard workers end up suffering from depression or burnout and lose not only their job but also their career or their beloved partners… It is not true to say that people fail, learn, and start again. Sometimes their failure is a definitive ruin.
So, here the secret I learned and which is my takeaway for you today:
Success requires performance.
It also requires a community of people recognizing this performance.
And above all it requires your survival.
Survival overcomes pure performance.
To your continued success
 Luca Delanna, Ergodicity: Definition, Examples, And Implications, As Simple As Possible. A great book I recommend.
 As an illustration, a business organization is often non-ergodic. A (cynical) HR VP calculates that “only 2%” of the workforce suffers from burnout. Yet this represents a probability of ruin of 100% for each of the individuals who overworked.
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