India, May 13 -- Justin Thomas had his caddie place hole-sized discs on every corner of the 17th green at Aronimink, all of them perched on knobs.

Whether he was chipping or putting, it was a challenge.

Aronimink is marked by its 180 bunkers that frame the landing areas, except for the longest hitters. The first official day of practice for the PGA Championship brought a reminder that accuracy this week is more about shots into the green than avoiding bunkers or the healthy rough.

These are big greens with big slopes.

"Off the tee it's not extremely challenging," said Keegan Bradley, who won on a soggy Aronimink in 2018 at the BMW Championship. "But the greens get really crazy, and they are really mounded and hilly just like a lot of ...