The progress has been steady, but hardly slow. It has, in fact, come at a rate no one — not even Tiger Woods — could have expected to be this fast. Twelve PGA Tour tournament rounds into a comeback from a fourth back surgery, which took place 11 months ago, Woods is in contention to win. Already. Woods’ comeback reached its dramatic pinnacle to date Friday as he surged to the lead at the Valspar Championship at Innisbrook in Palm Harbor, Fla. Woods, who began his round on the 10th hole in a morning-wave tee time, finished his second round on the Copperhead Course with a 3-under 68. Coupled with his 1-under 70 in the opening round, that had him tied for the lead at 4-under when he finished. By