World No.2 Adam Scott has continued his worrying trend of not being able to put together four good rounds, stumbling in the second round at the PGA Tour Championship to all but rule him out of contention.

Scott has been plagued by one round at par or worse over his past six tournaments, holding him back from contending, and his Friday two-over 72 at East Lake Golf Club is likely to bring the same result.

Dropping from three off the lead to a distant nine shots back of American Billy Horschel, and into a tie for 16th in the 29-man field, Scott now needs a miracle to claim the event he won in 2006.

The Queenslander still managed three top ten finishes in those past six events with his worst placing a tie for 16th, but he expects more.

It went pear shaped early on Friday with Scott three over on his first seven holes but he clawed back to even through 15 holes until an ugly double bogey on the 17th tomahawked his chances.

“I was disappointed with 17. It was a poor swing (into the water) and it was a tough time to do it so now I have to hope the leaders have a tough weekend and I have a good one,” Scott said.

He pointed to Morgan Hoffman as proof of a weekend surge with the young American shooting 15-under over the final two rounds last weekend to rocket to third in Denver.

“It’s a hard track, you have to play a lot of good shots to keep the momentum going but we have seen good scores here in the past,” Scott said.

“There is no doubt it is a big ask. Everything has got to match up but we saw how well Morgan Hoffman went last weekend so it is possible.”