The gist of it:

Inversion involves looking at a problem or situation from the opposite perspective or considering the reverse of the desired outcome. Instead of focusing on how to achieve a particular goal, inversion prompts you to think about how to avoid or prevent the unwanted outcome.

How to use it:

Inversion encourages a form of "backward thinking" that can lead to better decision-making, risk reduction, and problem-solving by considering what you want to avoid or prevent rather than just what you want to achieve.

Inversion encourages you to clarify your objectives by thinking about what should not do in order to achieve what you want. When you're stuck on a problem, thinking about the opposite scenario can reveal new insights and potential solutions.

Ask:

How can I win by not losing?

To get what I want, what should I avoid doing?

Deep Dive

“It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instead of trying to be very intelligent.” — Charlie Munger

The basic premise of Munger’s quote is that it is far easier and more effective to avoid making stupid mistake than trying to be brilliant - i.e. You can win in life by not losing.

The perfect analogy for this is the sport of tennis. In the book “Extraordinary Tennis for the Ordinary Player”, author Simon Ramo talks about how tennis could be subdivided into 2 games: Professional tennis (“Winners Game”) and amateur tennis (“Loser’s Game”). While the rules remain the same, the way points are scored for each are diametrically different.

In professional tennis, 80% of points are won while in amateur tennis, 80% of points are lost. Professionals need to work to score points by playing a nearly perfect game. They rally back and forth until one player hits the ball just beyond the reach of their opponent. In contrast, amateur tennis involves frequent mistakes with balls constantly hitting the net or out of bounds.

“The amateur duffer seldom beats his opponent, but he beats himself all the time. The victor in this game of tennis gets a higher score than the opponent, but he gets that higher score because his opponent is losing even more points.”
— Simon Ramo

The problem is most of us are amateurs trying to play the game of the professionals. What we should do when we’re the amateur is to invert the problem.

Rather than trying to win, we should avoid losing. As an amateur, if you choose to win at tennis (as opposed to having a good time), the strategy for winning is to avoid mistakes; be conservative and keep the ball in play. Let your opponent’s blunders win the game for you.

In problem solving, it is not enough to think about difficult problems one way. You need to think about them forwards and backwards. What do you want to avoid? Often times we don’t know the best path to succeed, but we do know the outcomes we want to avoid.

Inversion is a great mental model because it forces you to uncover hidden beliefs about the problem you are trying to solve.

For example:

Instead of asking yourself what you need to do to get a promotion, ask yourself what are the things you could keep doing to not get promoted. Then avoid doing those things.

If you are looking to foster a culture of collaboration at work, you’d think about all the things your organization could do to improve collaboration. If you look at the problem by inversion however, you would think about all the things the organization could do that would discourage collaboration. Ideally you would avoid these things. Sounds easy? Your company probably does some of those “stupid” things today.

“There must be some wisdom in the folk saying: it’s the strong swimmers who drown”” — Charlie Munger

Sources:
Extraordinary Tennis for the Ordinary Player
Inversion and The Power of Avoiding Stupidity
Inversion: The Crucial Thinking Skill Nobody Ever Taught You