A cash-secured put is a buy limit order the market pays you to place: you collect premium up front for promising to buy 100 shares at the strike, with the full strike × 100 in cash parked so assignment is a plan, not a margin call. Either the put expires worthless and you keep the premium, or you buy a stock you wanted at a price you chose — minus the premium you already collected.
Strike selection is odds selection, and delta is the shortcut: a 10-delta put gets assigned roughly one time in ten, while an at-the-money put is close to a coin flip. In the interactive builder (stock $100, 30% IV, 30 days), the $90 strike pays about $40 a contract — roughly 5–6% annualized on the secured cash with ~11% assignment odds — while the $100 strike pays ~$326 and ~40% annualized because assignment jumps to ~50%.
The fine print is the return shape from the skew lesson: short puts are negative skew — capped premium upside against a downside that runs nearly to zero. A $90 put sold for $0.40 on a stock that gaps to $60 loses $2,960 against a maximum win of $40, which is why the wheel's first filter is absolute: only stocks you want, at strikes you would pay with no premium attached, in sizes you can wear.
The lesson's builder computes premium, cash secured, annualized yield-on-cash, and approximate assignment probability live as you drag the strike, days-to-expiry, and implied volatility — so the yield/assignment trade-off stops being a slogan and becomes a dial you can feel.
Educational, not investment advice.