The Prerequisite Stack Test
Check whether a failed idea was actually wrong or simply arrived before its stack existed.
- Difficulty
- Easy
- Time to result
- ~weeks to results
- Steps
- 5
- Confidence
- 72%
Naval's mechanism is a timing audit. Every idea sits on a stack of previous innovations, the shoulders you want to stand on. When an idea fails, the usual conclusion is that it was a bad idea. The test says otherwise: list what the idea assumed was already in place, then check whether each prerequisite actually existed at scale and at price. Webvan and its peers failed in 1999 not because grocery and meal delivery were bad ideas, but because the enabling layers were missing. Instacart, Postmates, and DoorDash ran the same idea once the stack had arrived. Run in reverse, the test screens your own plans: count the prerequisites you would have to build yourself. A high count means you are jumping too far ahead and should either wait, or pick an entry point closer to what already exists.
Origin
Naval Ravikant states it while comparing the 1999 dot com failures with their successful later counterparts, in conversation with Matt Ridley about how innovation builds incrementally on what already exists.
Core principles
- 01Most failed ideas were not bad ideas; they were the wrong time.
- 02Every idea stands on a stack of prior innovations that must already exist.
- 03If the giants you want to stand on are missing, you are bootstrapping too much.
- 04The graveyard of dead startups is a shopping list once the stack arrives.
- 05Timing is a checkable condition, not a mystical quality.
How to run it
- 1
Decompose the idea into assumed prerequisites
List every technology, distribution channel, supplier, and user behaviour the idea takes for granted. Be specific enough that each item can be verified as existing or not.
Pro tip Include user behaviours and habits, not just technologies; those are the prerequisites people forget.
Watch out Vague prerequisites like better infrastructure cannot be checked and hide the real gap.
- 2
Grade each prerequisite
Mark each as present at scale and affordable, present but too expensive or immature, or absent entirely. The middle category is where most too-early ideas actually die.
Pro tip Check price and penetration, not mere existence; a technology that costs ten times too much is absent for your purposes.
Watch out Do not grade against what exists in your own bubble; grade against your target customer's reality.
- 3
Count what you would have to build
Anything absent is something you must build yourself before you get to your actual product. That count is the bootstrapping load, and it is the real cost of being early.
Pro tip One missing prerequisite can be a moat; three is usually a death sentence.
Watch out Teams routinely underestimate this count because they treat missing layers as small side projects.
- 4
Mine the graveyard
Take the failed ideas of the previous cycle and rerun the test against today's stack. Where the missing pieces have since arrived, the idea is live again and the demand has already been partly proven.
Pro tip Failed companies did expensive customer research; read their post-mortems before rebuilding from scratch.
Watch out Some ideas failed on unit economics or regulation rather than timing; confirm the cause before reviving them.
- 5
Set the trigger, then wait or move
If the idea is too early, name the specific prerequisite whose arrival makes it viable and set a trigger to revisit. Otherwise pick an entry point that stands on what already exists.
Pro tip Building a missing layer of the stack is often a better business than the too-early idea itself.
Watch out Waiting without a defined trigger means you will simply forget, and someone else will run it.
In the wild
Naval points out that the 1999 dot com bubble produced Webvan and Kozmo, which crashed, and pets.com, which crashed. The same ideas ran again a decade later as Instacart, Postmates, and DoorDash, and an online pet food business went on to sell for over half a billion dollars. Nothing about the ideas changed. What changed was the structure of previous innovations available to build on top of. In 1999 the giants to stand on did not yet exist, so the founders were trying to bootstrap too much at once.
→ Identical ideas failed and then succeeded, with stack availability as the only material difference.
Ridley describes realising, while writing about the Haber process that fixes nitrogen from the air, that it could not have happened without all the other industries around it in Germany producing the high quality metals and chemicals the process required. The chemistry alone was not sufficient. He argues the same holds in Silicon Valley, where one idea will not work without the neighbouring company producing the devices and programs your idea depends on.
→ A landmark process was gated by the availability of neighbouring industrial capability, not by the idea itself.
Common mistakes
Filing an idea under bad when it was early
Writing off a whole category because one attempt failed discards the market knowledge that attempt generated and hands the rerun to someone else.
Assuming you can build the missing layer on the side
Each absent prerequisite is a full product with its own timeline. Teams that plan to build two of them alongside the main product usually ship neither.
Grading the stack from inside the bubble
A prerequisite that is common among your peers may be absent for your actual customers, which makes an idea look ready when it is not.
Is it for you?
Best for
Founders choosing what to build next and investors screening ideas that already failed once.
Not ideal for
Genuinely novel research where no prior stack exists and building it is the point.
From the transcript
“Even a lot of the old ideas that failed weren't bad ideas. They were just the wrong time.”
“The previous innovation stack, the shoulders that you want to stand on, the giants don't yet exist. So you're trying to bootstrap too much.”
“They just need that right structure of previous innovations to build on top of.”
From the episode
Matt Ridley: How Innovation Works, Part 1
Matt Ridley