Harry Vardon is credited with inventing the "Vardon" grip, which involves the fingers of the hands overlapping. During the golf scenes, Vardon and Ouimet were using the "interlocking" golf grip, the opposite of the "Vardon" grip.
Going into the fourth round of the 1913 U.S. Open, Ouimet trails Vardon and Ray by one stroke. However, the final leader board shows all 3 shooting 79, with a total of 304 strokes for the tournament. That means all 3 were tied entering the fourth round.
During the playoff, Harry Vardon's ball blocks Francis Ouimet's ball's path on the green, a play called a "stymie." That only applied to singles match play. The playoff for the 1913 US Open was medal (stroke) play, and the stymie rule would not have applied. The USGA eliminated that rule in 1952.
The 17th hole of The Country Club is shown as a dogleg right, and Harry hits his ball into an unseen trap on the right side of the corner of the dogleg. In 1913, The Country Club's 17th hole was a dogleg left, and Vardon hit his ball into a trap on the left side of the fairway.
Francis looks at a yardage book, a series of hand-drawn diagrams of every hole at The Country Club. Yardage books did not come into use until the 1960s, first by Deane Beman, later popularized by Jack Nicklaus.
The opening shot begins with a scene set in Jersey, overlaid with the caption "Isle of Jersey, England". Jersey is one of the Channel Islands, and the main island of the Bailiwick of Jersey. It's a British Crown Dependency with its own administration. The King or Queen of England is the head of state in their capacity as the Duke of Normandy. It's closer to France than to England, and is neither geographically nor administratively part of England.
In the playoffs Ouimet shot 72, Vardon 77 and Ray 78, but the scoreboard had Vardon with a 73 and Ouimet needing the final putt to win. Ouimet was up one going to No. 17 when he birdied while Vardon shot bogey. At No. 18 Ouimet posted a par to Vardon's double-bogey.
When Vardon's ball lands in rainwater in a sand trap, he stands in the water and plays the ball out of the water. The rules of golf clearly state that occasional water entitles a free drop: "If your ball comes to rest in casual water within a bunker, you may drop without penalty at the nearest point of relief within the bunker, no nearer the hole. That applies no matter what the condition is of the rest of the bunker."
When John McDermott is shown falling to the ground after hitting his ball into the woods, there is a close-up of his anguished face and of his grip. McDermott was known to have had an unusual overlapping grip, with only 8 fingers touching the shaft. In the scene, the actor is using a baseball grip. While Scott Piercy and Tommy Gainey are two well- known golfers who employ a 10-finger grip, most golfers use either an interlocking or overlapping grip. Hand a golf club to someone who has never swung one and you'll most likely see that person use a baseball grip, not because he or she knows the golf game, but because they don't know the subtle nuances and intricacies of the game.
In the playoff round, a quick pan across the 3-player scoreboard shows Ouimet and Vardon tied at Even. Below their score is Ted Ray at +6. When the pan is reversed frame-by-frame, Ray is really only at +3..
The goof items below may give away important plot points.
The father of the main character, Francis Ouimet, is a French immigrant who speaks English with a French accent. The movie covers at least 12 years, so his spoken English should improve. Instead, it gets worse.