This "by the numbers" was provided by the PGA of America.
Bone up. There will be a test at the end of the week.
3 Times the PGA Championship has now been held at Valhalla Golf Club
4 Times that Tiger Woods has won the PGA Championship
5 Record for most PGA Championship victories -- Walter Hagen and Jack Nicklaus
15 PGA Champions in the field for the 2014 PGA Championship
20 PGA Club Professionals in the field
21 Age of Jordan Spieth, youngest player in the field
23 Players in 2014 PGA Championship field who competed in the 2000 PGA Championship at Valhalla
24 Countries represented in the field
29 Major champions in the field
33 PGA Championship appearances by Tom Watson, ranking him third all-time (Jack Nicklaus and Arnold Palmer have 37 each)
64 Age of Tom Watson, oldest player in the field
67 Players who have won the PGA Championship since 1916
71 Par at Valhalla Golf Club for the 2014 PGA Championship
72 Par at Valhalla Golf Club for the 1996 and 2000 PGA Championship
270 Winning 72-hole score in the 2000 PGA Championship (shot by both Tiger Woods and Bob May, with Woods prevailing in a playoff)
277 Winning 72-hole score in the 1996 PGA Championship (shot by both Mark Brooks and Kenny Perry, with Brooks prevailing in a playoff)
7,458 Official yardage of Valhalla Golf Club for the 2014 PGA Championship
Source: 2014 PGA Championship By the Numbers
Bone up. There will be a test at the end of the week.

4 Times that Tiger Woods has won the PGA Championship
5 Record for most PGA Championship victories -- Walter Hagen and Jack Nicklaus
15 PGA Champions in the field for the 2014 PGA Championship
20 PGA Club Professionals in the field
21 Age of Jordan Spieth, youngest player in the field
23 Players in 2014 PGA Championship field who competed in the 2000 PGA Championship at Valhalla
24 Countries represented in the field
29 Major champions in the field
33 PGA Championship appearances by Tom Watson, ranking him third all-time (Jack Nicklaus and Arnold Palmer have 37 each)
64 Age of Tom Watson, oldest player in the field
67 Players who have won the PGA Championship since 1916
71 Par at Valhalla Golf Club for the 2014 PGA Championship
72 Par at Valhalla Golf Club for the 1996 and 2000 PGA Championship
270 Winning 72-hole score in the 2000 PGA Championship (shot by both Tiger Woods and Bob May, with Woods prevailing in a playoff)
277 Winning 72-hole score in the 1996 PGA Championship (shot by both Mark Brooks and Kenny Perry, with Brooks prevailing in a playoff)
7,458 Official yardage of Valhalla Golf Club for the 2014 PGA Championship
Source: 2014 PGA Championship By the Numbers