Eight notable second-round stats from Golf World contributing writer Brett Avery, who compiles the Rank and File statistical sections for the magazine's major championship coverage. For more numbers throughout each round, follow him on Twitter (@BWAvery):
Five of the top 10 players in the World Ranking missed the cut at three-over-par 143: Luke Donald (ranked No. 1, shot 146), Lee Westwood (second, 144), Matt Kuchar (seventh, 151), Graeme McDowell (ninth, 145) and Nick Watney (10th, 145). Another four in the next 10 also will miss the last 36: Ian Poulter (16th, 147), Robert Karlsson (18th, 146), Tiger Woods (19th, injured) and Hunter Mahan (20th, 144). Just 13 of the top 30 made the cut and 26 of the top 50.
On the flip side, of the 71 players who began the week outside the top 100, 25 made the cut. That's 35.2 percent, versus 43.3 percent of the top 30.
Eight players outside the world 300 fought their way into the reward of battling Royal St. George's two more times:
--Floris de Vries (ranked 312nd, T-59 through two rounds)
--Kenneth Ferrie (365th, T-45)
--Richard McEvoy (401st, T-32)
--Tom Lehman (406th, T-7)
--Tom Watson (611th, T-45)
--Matthew Millar (917th, T-59)
--Amateurs Tom Lewis (937th, T-14)
--Amateur Peter Uihlein (unranked, T-45).
Phil Mickelson's 70-69 put him in a tie for 14th, three behind co-leaders Darren Clarke and Lucas Glover. This is Mickelson's 18th start in the Open Championship but only the second time he totaled lower than 140 at the midpoint. The other instance? He went 73-66 at Royal Troon in 2004 and wound up solo third.
Speaking of uncharacteristically low starts, Clarke's 68-68 marks only the second time in his Open Championship career that he began with two rounds under 70. He went 67-66 in 1997 at -- wait for it -- Royal Troon and tied for second.
Clarke has had some difficulties this European Tour season when he's opened with a pair of low scores. This was the fourth time this year he's kicked off a tournament with two sub-70s. He closed 67-73 and tied for eighth at the Volvo Champions, went 81-75 and placed solo 77th in the Trophee Hassan and shot 75 and tied for 66th in the rain-shortened Scottish Open.
In his first eight major championship starts since making the U.S. Open his breakthrough title, co-leader Glover has missed three cuts and finished in the top 35 just once: solo fifth in the '09 PGA. His scoring average in majors during those events: 72.92.
The field scoring average was 72.974, nearly a shot higher than the first round. The fourth hole ranked the most difficult (4.613), followed by the eighth (4.432), the 11th (3.355), the 17th (4.316) and 18th (4.303). The seventh played the easiest (4.400). Driving distance at the two measured holes, the 13th and 15th: 307.8 yards. Fairways hit: 46.9 percent. Greens in regulation: 56.7 percent. Cost of rough: 0.305 strokes.