SAN DIEGO (AP) — Phil Mickelson is leaving nothing to chance at this U.S. Open. It’s not his last chance to win the only major keeping him from the career Grand Slam. But he turns 51 on the eve of the U.S. Open. Time is not on his side. This U.S. Open is at Torrey Pines in his hometown of San Diego. Mickelson has the confidence of winning the PGA Championship last month to become golf’s oldest major champion. That’s why he spent so much of last week trying to learn every nuance of the South Course to give himself the best shot.