Beat the planning fallacy by multiplying effort and time far beyond your first estimate

Teams chronically underestimate. Psychologists Daniel Kahneman and Amos Tversky called this the planning fallacy: we predict the best case, even when we know better. A manager says, “Two weeks, tops,” then watches scope creep and delays turn it into six. The calendar fills, emails pile up, and the original momentum thins to a trickle. People are not lazy, they’re optimistic, and optimism without data is expensive.

High performers flip the script. They run a pre‑mortem, a simple exercise from organizational psychology. Before starting, they assume the project already failed and list plausible causes. That short list changes how they plan. Suddenly, “slow legal review” becomes 10 extra days, “stakeholder buy‑in” becomes three additional meetings, and “my own context switching” becomes protected, uninterrupted blocks on the calendar. The office hums, phones buzz, and yet the plan stays anchored in base rates, not hope.

Then comes the controversial move: multiply critical inputs by ten and front‑load them. If the last campaign took 200 cold emails to land five demos, they schedule 2,000 sends and 600 follow‑ups, with 800 in week one. It feels excessive on paper, but in practice it buys speed and truth. One founder told me he thought 15 investor meetings would be enough. He booked 150, and by meeting 30 he had the pitch tight and two term sheets inbound. A designer thought a draft would take three hours. She blocked six, finished early, and used the extra time to test a risky concept that won the client.

The science is clear. Pre‑mortems reduce overconfidence by forcing concrete failure scenarios. Base‑rate reasoning uses outside data (your past) to correct rosy assumptions. Multiplying inputs counters the power law in response rates and the reality of drop‑off. Front‑loading taps the “fresh start effect,” increases exposure to feedback early, and creates slack for inevitable surprises. It’s not about working recklessly, it’s about planning with math and acting with urgency.

Start with a quick pre‑mortem: assume it’s two months from now and the project flopped, then write ten reasons. Pull up your last three similar efforts and use their real time and outreach numbers as your new baseline. Now pick two critical inputs—like messages sent and follow‑ups—and plan for ten times your first guess, pulling a third of that work into week one to expose reality fast. Book the blocks on your calendar today and let the early momentum tell you what’s true by Friday.