Course setup is the defining variable. The championship is known for narrow fairways, punishing rough and firm, fast greens, the scoring average climbs, and par holds value in a way it rarely does elsewhere. That pushes the emphasis toward driving accuracy, scrambling and patience rather than raw distance, and it flattens the field, since players who avoid disaster holes can hang around without elite ball striking. Cut markets, top ten finishes and first round leader prices tend to stay interesting because scores bunch together.
The U.S. Open is one of the four men's majors in golf and sits on the PGA Tour schedule. It runs over four rounds with a cut at the halfway point, the field mixes exempt players with those who come through open qualifying, and a tie is settled by a playoff.
The week also moves in stages. Greens firm up round by round as the surface dries, so a number that leads the opening round can be several shots off the pace late, and the draw matters because morning and afternoon groups often face a different golf course. Local qualifying puts unfamiliar names on the early leaderboard, and most of them drift back as the setup hardens. Attrition is the theme of the closing round, when leaders come back to the field more often than they pull away.