What Is Inversion?

Last updated
October 1, 2026
In decision-making, inversion is the act of asking the opposite of the question you would normally ask first. It is usually the not-obvious one, which is why the answer to a stalled problem so often sits there.
  • Charlie Munger borrowed the phrase "invert, always invert" from the 19th-century mathematician Carl Jacobi and used it to ask what would guarantee failure before asking what would produce success. If you only ever ask the forward question, you are working from half the picture.
  • The obvious question and its opposite rarely get the same answer. Ask your team how to hit a target and they list actions to take; ask what would guarantee missing it and they tend to name blockers nobody had said aloud.
  • A quick way in is to write down the question your team is already asking, then write its opposite. If nobody has tried to answer the second one, start there.
  • Inversion gives you a new angle and leaves the plan to you. Once the opposite question has an answer, you still have to build something with it.

Why Does Asking the Opposite Question Solve a Stuck Problem?

Inversion works because the obvious question and its opposite draw on different information. Your team has usually spent a long time on the question everyone asks first, and by then it has stopped producing new answers. The opposite question has had far less attention, so it still has something in it.

This shows up in meetings as a brainstorm that stalls on one question and starts moving the moment you flip it. A session that has produced nothing new on "why didn't the other 20 accounts buy" can change direction fast once someone asks "what did the 5 that bought have in common". The first question hunts for what went wrong, and the second finds what already works.

Inversion also helps with indecision. When every forward option looks equally uncertain, ask what would make each one fail and you have something to compare: the option with the fewest ways to fail.

The practical tell is a brainstorm that has produced nothing new in the last few minutes. That is usually the moment to ask the opposite question instead of pushing harder on the same one. Write the answers down, then check your current plan against each one.

What's a Real Example of Inversion Solving a Stuck Sales Problem?

After the first month of a new-business push, 25 accounts had opened but only 5 had placed an order, nowhere near enough to reach our £1,000,000 target. We worked through ideas, a first-order discount and a new welcome pack among them, and I still felt we were missing something. The answer came to me in the shower: we had spent the meeting asking why the 20 hadn't ordered and never why the 5 had. Every one of the 5 had been visited by a sales rep within a week of opening the account, and that window, our "golden hour", became the whole fix, with no discount and no new welcome pack.

Even leaders who know to invert a problem still invert once and take the first opposite answer as complete. The real value shows up on the second or third pass, when the obvious answers are exhausted and the less obvious ones start to surface.
sources
  1. Kaufman, P. D. (Ed.). (2005). Poor Charlie's Almanack: The Wit and Wisdom of Charles T. Munger. Munger attributes "invert, always invert" to the mathematician Carl Jacobi.
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