What are key numbers in NFL betting?

Key numbers in NFL betting are the most common margins of victory: 3 (field goal), 7 (touchdown + extra point), 6, 10, and 14 are the most important. Lines at or near these numbers carry extra significance because games land on them frequently. Paying a small premium — like -120 instead of -110 — to get a spread of -2.5 instead of -3 is often worth it.