Francesco Molinari’s two-stroke victory in the 2018 British Open, the first major golf championship ever by an Italian player, translated to a pedestrian -2.14 Z Score.
Molinari defeated a field of challengers that included three highly ranked players. Tiger Woods, who ranks first on the peak rating chart, tied for sixth with a Z Score of -1.47. Rory McIlroy, a three-time major champion, tied for second at -1.69. Jordan Spieth, who ranks just outside the top 10 on the all-time peak list, tied for ninth with a -1.24 peak score.
Even so, Molinari’s victory was unremarkable by the standards of previous British Opens. The 25 most dominant British Open performances have all been achieved with Z Scores of -2.73 or better. (A Z Score is a measure of exceptionality based on the standard deviation of the player’s performance. Molinari’s -2.14 score means he performed at a rate that was 2.14 standard deviations better than the average of all players completing four rounds at Carnoustie.) None of the 25 most dominant British Open performances, by the way, have been achieved at Carnoustie, which has now hosted the Open eight times.
Despite Molinari’s victory being the first ever in a major championship by an Italian, it is not the most dominant performance by an Italian player. When Costantino Rocca lost a playoff to John Daly for the 1995 Open championship, both players finished with a -2.21 Z Score.
Here are the 10 most exceptional British Open performances in history based on winning Z Score:
Rank Player Year Course Z Score
1 Louis Oosthuizen 2010 St. Andrews -3.51
2 Henrik Stenson 2016 Royal Troon -3.50
3 Tom Watson 1977 Turnberry -3.38
4 Tiger Woods 2000 St. Andrews -3.33
5 Tom Watson 1980 Muirfield -3.26
6 Jordan Spieth 2017 Royal Birkdale -3.25
7 Arnold Palmer 1962 Royal Troon -3.15
8 Henry Cotton 1934 Royal St. George’s -3.13
9 Johnny Miller 1976 Royal Birkdale -3.11
10 Nick Faldo 1990 St. Andrews -3.09