Imbellus Ecosystem: Does everyone endup with 8 surviving species? Does the correct answer always exist?

Question

Just finished the official PSG, and had only 7 species surviving. Do all games have the correct answer? Or are some games impossible to get 8 species? Never heard of this scenario before. Is it certain that all games are solvable?

1. What I did before the actual PSG:

I prepared rigorously with Francesco's videos and the MC Simulation for 3 days to perfect every detail with a friend.
By the end of my preparation, we had optimized our framework (MECE+efficient) and details to every click.
I could solve all simulations within 15mins, with at most 20 species opened/checked and less than 40 mouse clicks. (Stable performance during ~10 mocks)
I pre-printed sheets for each stage of analysis to decrease human error and increase efficiency.
And the list goes on…

2. What happened during the actual PSG:

As planned, I divided the height into 3 categories based on total calories from producers.
I started with the optimal height with the most calories from producers. Then I realized that only 7 could survive with bottom-up and top-down approaches. (Re-examined with my note afterward with all combinations, quite certain.)
Then I went for the second height, and again only 7 could live. In one combination, the 7th prey had 2600 cal provided, while its only predator had 2600 cal needed. In the end, I went with this solution before running out of time. (Less certain about the second height, due to the time limit I did not record every piece of data.)

3. So this can happen? Or is it certain that the game is solvable, I just did not reach it?

Wanna hear if anyone had a similar experience, or is it guaranteed that a right answer does exist?

Answer 1

Hey there,

Very likely that McKinsey introduced these changes as I am getting similar reports (same as that the plant defense is getting replaced as well with a new game).

It makes sense since they have been adjusting the game ever since they launched it. I have written and published the first guide for it in Nov 2019 already and have gone through countless bigger and smaller iterations since then.

Based on your prep, I would not worry about it.

Cheers,

Florian

Answer 2

Hi,
I have never heard about an impossible 8-species ecosystem to create, but I confirm candidates get invitations even without being perfect on this game, so..finger crossed!

Best,
Antonello

Answer 3

Hi there,

This is really interesting.

I honestly haven't heard of this yet, but it sounds like you were well prepared and really considered all scenarios.

Here's what I do know: nothing is ever a sure thing with these interviews. They are always changing the games, the format, the questions, etc.

So, it does sound like they may have changed it a bit to allow for only 7.

Answer 4

Hello,

I haven't heard of such a scenario, but it is probable that they may have changed something in the game so that some scenarios only have 7 species surviving now, particularly as others here seem to have heard of such experiences too. In any case, I wanted to reiterate Antonello's advice that you don't have to be perfect on the game to get an interview offer, so I wouldn't worry too much about it given that it's happened now. Best of luck!

Answer 5

I just took it now and had a similar experience, I’m not really sure if all 8 species could survive I only got 7 to survive

Answer 6

I took the test last week. Like you, I divided the height into 3 categories based on total calories from producers. I started with the second most optimal height, then changed to the most optimal. Having failed to research the game in advance (don't ask) I did my best, on the fly. It was only afterwards, that I realised that 8th animal (blacktail jackrabbit) ate only miners lettuce, which (according to my notes) produced 450 calories less than the jackrabbit needed. As best as I can figure, I think I fell for a trick. Clearly, I would have done better if I had prepared! My ecosystem of was sustainable (without the miners lettuce and the jackrabbit). I don't know yet if I passed, but I enjoyed the experience enough that I will prepare and aim to take the test again if I didn't pass this time.