"The obvious thing is intelligence… You can tell that really quickly, much less than 10 minutes." Intelligence is table stakes and screens fast — it's not the bottleneck in the decision.

Clarity of vision is a key signal: can the founder articulate, simply and precisely, what they're building and why it matters?

Communication skills act as a proxy for many other founder abilities — recruiting, selling, fundraising — and are highly legible in a short conversation.

Sam looks for non-obvious brilliance of the idea — the kind of insight that sounds surprising or even wrong at first but reveals depth on inspection.

Sam initially didn't believe a 10-minute interview could beat random selection. Experience changed his mind: you don't need 100% accuracy, just enough signal for the business model to work.