Winged Foot: The toughest US Open course

Field standard deviation

This measurement is similar to the previous one we looked at with respect to standard deviation. A smaller one – below about 4.75 — indicates a field largely performing in a course-neutral environment. A larger one – in excess of 6.5 – suggests a course-directed impact that puts the players more at the mercy of the layout. A standard deviation between 4.75 and 6.5 would be a “normal” range on tour.

From largest to smallest, here’s the table.

Average standard deviation

Oakmont                             6.37

Winged Foot                      6.33

Oakland Hills                      6.22

Baltusrol                              6.11

Olympic                                5.50

Merion                                 5.28

Shinnecock                         5.27

Pebble Beach                    5.00

By this standard, Oakmont appears to exert the greatest influence on field performance over time. But Winged Foot and Oakland Hills are a close second and third.

Meanwhile the margin between the fourth and fifth most influential layouts – Baltusrol and Olympic – is more than twice the margin separating the fourth and fifth most influential.

As a general rule, the standard spread of field performance has shrunk over time, and that’s also true at Winged Foot. When Jones won in 1929, the normal spread between entrants – a mathematical term designed to encompass about two-thirds of all players — measured 8.75 strokes. That is, about two-thirds of the field fit within that 8.75 stroke window…about four and a quarter strokes on either side of the average.

By 1959 when Casper won, that normal spread had declined to 6.46 strokes. It has continued to decline since; to 5.42 strokes in 1984 and to 4.55 strokes in 2006. Over time, competition intensifies itself.