The American world number one missed three putts from inside five feet and failed to birdie any of the three par-fives as he carded a five-under-par 66 on a breezy day at Conway Farms Golf Club.
"Well, I certainly wasted a lot of shots out there today," a disgruntled Woods said after finishing three strokes behind pacesetting American Brandt Snedeker. "I missed three short ones and played the par-fives stupendously.
"One of those days. I'm not exactly real happy. I played well, and I just didn't get much out of that round. As I said, I missed three little short ones in there and then played the par-fives even par. That's just not very good."
Woods, who has won a season-high five times on the US Tour, felt the scoring overall was a little better than he had expected, given the blustery conditions.
"It's a little bit lower considering the wind," said the 14-times Major winner, who mixed seven birdies with two bogeys to end the day level with fellow Americans Steve Stricker and Kevin Streelman, and South African Charl Schwartzel.
"The guys really took advantage of it today. The greens weren't as fast as they were yesterday, and you certainly could be a lot more aggressive ... you could be really, really aggressive."
Woods has an impressive track record in the Chicago area, twice clinching the US PGA Championship at nearby Medinah and visiting the winner's circle on five occasions at Cog Hill, which previously hosted the BMW Championship.
Though this is the first time he has competed on the par-71 layout at Conway Farms, he felt the biggest test on Thursday was adjusting to the greens.
"More than anything I think it's just reading the greens," said Woods, who occupied second place in the FedExCup standings going into this week's tournament, the penultimate event in the US Tour's lucrative play-off series.
"The familiarity, I just don't quite have it, and some of the putts are a little bit tricky here and there. But (caddie) Joey (LaCava) did a great job of getting the numbers and getting a feel for the golf course.
"We talked about it at length yesterday as we were playing the pro-am, what the wind direction was going to be for today and tomorrow and had a really good game plan."