The number that kills more deals than any other: repairs.
People run the rent, subtract the mortgage, see cash flow, and buy. Then the roof, the HVAC, or the turnover eats a year of profit in one check.
Before you fall in love with a cash flow number, ask what it looks like after you set aside for capex and vacancy. A deal that clears $400/mo on paper but has a 15-year-old roof isn’t really a $400 deal yet.
Cash flow is what’s left after the house takes its cut — not before.
