"Handicap" refers to a numerical representation of a golfer's playing ability. Handicaps are meant to represent a golfer's potential rather than simply be an average of a golfer's scores. While professional golfers do not normally maintain handicaps, their handicap can easily be calculated by entering their tournament scores into a handicap calculator. Here is a link to a guy that once calculated Tigers handicap.
According to his calculations, Tigers handicap during that stretch was an astonishing +13.5. Most tour players average around +5 or +6. I do recall back in the early 1990s where a golf magazine calculated Greg Norman's handicap at around +9. Suffice it to say, tour pros are 5 to 13 strokes better than a scratch golfer.
What I find most remarkable is that these scores are obtained under tournament conditions, with fast greens and high rough, in front of millions of people, playing for millions of dollars!
As of June 11, 2013: Tiger's Hanicap is +6.3 according to Score18.com: