A hat tip to Ryan Ballengee’s Twitter feed for pointing me to an awesome post at Rexford Buzzsaw, which takes a sabremetrics-type of look at golf. If you’re not into advanced stats, this post probably isn’t for you.

You’ll hear players and commentators talk about the luck of the draw, and how that makes it tougher or easier to score. In the last two days at the British Open, players going off in the morning had a considerable scoring advantage. No one better illustrated that than poor first-round leader Rory McIlroy, who went 63-80.

Was Thursday 17 strokes harder than Friday? Of course not. But the following averages essentially quantify what par was at certain tee times by calculating a weather-adjusted score. Wondering how Mark Calcavecchia (above) is in second place? Well, his early morning 67 weather adjusted is just 71.2, because the scoring conditions (rain, no wind) were so much better than what the rest of the field faced. So he had a massive advantage.

Tiger Woods’ 73 in 40 mph winds when finishing nearly 12 hours later? 71.3.

The weather-adjusted score basically means — I’m over-simplifying this, there’s a lot of math — if everyone in the field played in the exact same conditions, this is what they’d shoot, readjusted in relation to par to the field average for the day.

Of course, this doesn’t change anything about the leader board in real life, but the weather-adjusted score is a great indicator of who is playing well, and who to keep an eye on this weekend. Again, it is explained much better here. Now, your weather-adjusted leader board:

Louis Oosthuizen	65.48	71.35	136.827
Nick Watney	68.27	69.88	138.152
Retief Goosen	67.77	70.40	138.164
Sean O’Hair	68.29	70.02	138.308
Lee Westwood	66.25	72.15	138.392
Paul Casey	68.39	70.42	138.812
Graeme McDowell	70.09	68.88	138.977
Tiger Woods	68.28	71.08	139.360
Martin Kaymer	68.42	70.95	139.371
Miguel Angel Jimenez	71.25	68.15	139.392
Peter Hanson	65.54	74.70	140.237
Heath Slocum	67.66	73.19	140.849
John Daly	67.17	73.91	141.080
Marcel Siem	67.97	73.12	141.092
Trevor Immelman	69.23	71.87	141.106
Ricky Barnes	67.93	73.61	141.544
Sergio Garcia	69.93	71.63	141.568
Thomas Aiken	69.05	72.55	141.600
Danny Chia	66.03	75.73	141.763
Andrew Coltart	67.17	74.91	142.080
Toru Taniguchi	69.81	72.30	142.103
Robert Karlsson	68.81	73.30	142.103
Rory McIlroy	64.28	77.90	142.183
Lucas Glover	68.28	73.90	142.183
Mark Calcavecchia	70.57	71.73	142.300
Camilo Villegas	69.28	73.08	142.360
Adam Scott	71.25	71.15	142.392
Ryo Ishikawa	69.26	73.15	142.417
Tom Lehman	71.28	71.62	142.898
Simon Dyson	70.08	73.00	143.076
John Senden	69.03	74.05	143.082
Dustin Johnson	68.81	74.30	143.103
Phil Mickelson	71.77	71.40	143.164
Ian Poulter	72.29	70.97	143.261
Y.E. Yang	66.93	76.61	143.544
Richard S. Johnson	71.05	72.55	143.600
Alvaro Quiros	71.67	71.99	143.668
Edoardo Molinari	67.60	76.17	143.765
Vijay Singh	68.05	75.94	143.990

Some names that jump out? Well, Louis Oosthuizen (-12) shaved off around four strokes from his Friday score because he went off in the morning. Calcavecchia (-7)  has improved five strokes because of the breaks in the weather he’s caught, while Nick Watney (-4), shot a brilliant 73 on Friday, which converts to a weather-adjusted 69.88. Rory McIlroy (-1) certainly didn’t play well Friday, but his 80 gets reduced to a weather-adjusted 77.90. Sean O’Hair (-5) posted the best round after the wind delay, but his 72 is weather adjusted to 70.02. Phil Mickelson (even) has a nearly identical weather-adjusted score as Dustin Johnson (3-under), but DJ has caught the better conditions.

Why is this important?

Over a long period of time, this stuff is just random and will even out. Over four rounds of golf, some players get a huge advantage. This is the same thing that happened at Bethpage last year.

Something to watch on Saturday is if the same weather trends continue (easy early, brutal late), players in the even par/1-under/2-under boat could be playing a course four or five strokes easier than what the leaders will face. That means the guys at the bottom can make a move, and the guys at the top might come back to the pack.