Justin Leonard and Phil Mickelson are tied for second with 36-hole scores of 6-under 134, just one shot behind Retief Goosen.
Leonard, ranked No. 101 in the world rankings, said a few changes in the position of his club has helped.
``It was one of those things where it was time to do it,´´ Leonard said. ``Band-Aids weren't going to last much longer.´´
Leonard said Randy Smith and Brian Smith assisted in the change.
``I've always kind of approached this game as being more of a marathon than a sprint. Willing to take a step back on order to take two steps forward. Hopefully these last couple of weeks are those two steps forward.´´