63 - Dustin Johnson leads after 36 holes thanks to a flawless round of nine under par.
67.8- Johnson's stroke average in his last ten WGC stroke play events is 67.8.
4- The World Number One's round was four strokes better than any other player's.
3- Johnson is the third man to shoot a second round 63 in this tournament, after Ernie Els (2012) and Louis Oosthuizen (2011 and 2012).
130- The American's 36-hole total of 131 is one shy of the record for this event, set by Kevin Kisner in 2015.
8- The average World Ranking of tomorrow's final group - Johnson (1), Brooks Koepka (11) and Justin Rose (13) - is eighth.
36- Peter Uihlein and Charles Howell III were the biggest movers on Friday, climbing 36 places each. Both men have posted scores of 72-67 so far.
23- Jon Rahm and Peter Uihlein took the fewest putts on Friday, with just 23 each.
8 - Eight of the top nine players after 36 holes are in the top 35 in the Official World Golf Ranking.
486- The 486-yard par four ninth hole has proved the toughest this week. Only 15 birdies have been recorded there, with 43 bogeys and nine double-bogeys or worse.
87- There have been 87 birdies on the 550-yard par five second hole, the easiest hole of the week.