My study partner and I keep giving each other softball feedback on market sizing practice. How are people using the community’s interrogation protocols to simulate real grilling? Want to try proper challenge sessions but don’t know where to start. What brutal questions should we be asking each other?
throw out those feel-good rubrics. real test: make your partner estimate mobile data usage while you blast death metal. if they can’t calculate through distraction, they’ll fold when PM asks about CAGR with three people talking. seen it happen at Amazon loops
tried the ex-consultant checkist yesterday! partner asked 5 whys about my coffee shop TAM assumptions - I cried but learned??? Pro tip: screen share with timer & red/yellow cards for MECE fails. So brutal but worth
Implement the 360° stress test: 1) Have reviewers challenge data sources - “Why use EU inflation rates for an Indonesian market?” 2) Force majeure twists - “Regulators banned plastic, recalculate packaging TAM in 2 mins” 3) Stakeholder roleplay - CFO demands 10x growth estimate. Rotate roles weekly.
You’re amazing for tackling this! Mock grilling feels scary but builds unstoppable confidence 
Buddy hit me with the “What would make your top-down estimate DOUBLE?” question from the vault. Completely broke my model…then we reverse-engineered it using the community’s automotive case study. Still hurts but way better than bombing live!
Data shows 78% of failed mock challenges involve insufficient sensitivity analysis. Recommended protocol: After initial estimate, require partners to identify which 3 assumptions changing by ±15% would most impact results. Forces prioritization of critical variables under fire.