BETHESDA, Md. — Roberto Castro likes Congressional because he says it's "right in front of you," a common phrase from players who like the look of a golf course without really knowing why except for the low score on the card.

Castro made a valid point Thursday in the most simplistic terms at the AT&T National, where he opened with a 5-under 66 for a two-shot lead.

"You have to go just stripe a driver," he said. "There's not many good breaks or bad breaks to be had out there," he said. "If you drive it in the rough, you drove it in the rough. If you hit in the fairway, you can go from there."

Just his luck, the first driver he hit found the fairway and he made his only bogey — an approach into the water and a nifty up-and-down to limit the damage. The rest of the day was a combination of keeping the ball in play, and making some timely putts when he found himself in the thick rough.

Congressional is as long as any course on the PGA Tour schedule and it has the pedigree of hosting the U.S. Open three times. So strong is this course that the AT&T National at times felt like a U.S. Open — just as it did last year, and how it likely will be the rest of the week.

"It's very similar in that there's not a lot of birdies out there," Castro said.

The average score was just over 73, despite cloud cover for most of the day leading to soft conditions and only a light wind.

Billy Horschel, who tied for fourth in the real U.S. Open two weeks ago, began his day with a 50-foot birdie putt, added a pair of birdies over the next three holes and then hung on for a 68. That was the best score among the early starters. Bud Cauley and Graham DeLaet each had a 68 in the afternoon.

"It's like another U.S. Open," Horschel said. "Off the fairways, the rough is thick. Fortunately, the greens are soft so they're really receptive. It's still a tough golf course."

The eight players at 69 included Jim Furyk, 19-year-old Jordan Spieth and Brandt Snedeker, whose round included a birdie on the par-5 ninth hole in which he covered more than the 635 yards it was playing.

Snedeker snap-hooked his drive into the rough and was blocked by trees, leaving him no choice but to chip backward or play down the adjacent fourth hole. He hit hybrid down the fourth, and just his luck, wound up on the member's tee. From about 180 yards, he hammered a 6-iron through more trees, and the big roar told him he had reached the green. From there, he made a 55-foot birdie putt. Simple as that.

"Kind of stealing a couple there is what it feels like," he said.

Furyk was grinding away at 1 under — two birdies, one bogey and 13 pars — when he got to the seventh tee (his 16th hole of the round) and saw a scorecard that showed him on the first page of the leaderboard. That's when he realized that low scores were going to be at a premium.

"It's a hard layout to start with," Furyk said. "I don't know if the golf course was unfair. After the U.S. Open came, they didn't widen out the fairways. Before the U.S. Open, these fairways were much wider than they are right now. They kept the U.S. Open lines. The rough isn't U.S. Open hard, but it's still difficult."

The most recent U.S. Open was in 2011, when rain and little wind made Congressional vulnerable, and the emerging Rory McIlroy bludgeoned it with a record 16-under 268 for an eight-shot win and his first major.

Lucas Glover, a former U.S. Open champion, called it "the most boring round of PGA Tour golf I've heard."

"I heard two cheers across the whole golf course all morning," Glover said after a hard-earned 71. "They definitely weren't for my group."

There were no tricks at Congressional, and there certainly was no faking it. Masters champion Adam Scott hurt himself with an ordinary day by his standards off the tee and wound up with a 73. Hunter Mahan hit only six fairways — he's one of the best drivers in golf — and shot a 75.

Castro bounced back from that early bogey on No. 11 with birdies on the next two holes, and then he ran off three straight birdies toward the end of his round that required some highly skilled shots — a 20-foot putt on No. 5, a perfect 3-wood to about 15 feet for a two-putt birdie on the par-5 sixth, and a chip-in just off the seventh green.

But it was a quiet day for the most part.

"Two U.S. Opens in three weeks," said George McNeill, who had a 71 while playing with Jonas Blixt and Ben Curtis. "And before that, we got to play the U.S. Open at Muirfield (Village), too. It was fairly quiet out there. You have a few cheers here and there. But we had the 'hot dog' group. That's where the fans are looking at the pairing sheet and go, 'Curtis, Blixt, McNeill. Let's go get a hot dog.'"

It didn't help that Tiger Woods wasn't around, unable to play because of a sore left elbow that will keep him out of competition until the British Open next month.

Woods won last year at 8-under 276, one of the higher winning scores on tour in 2012.

"You don't usually see first-round scores on a PGA Tour event only be 3-under leading after the morning wave," Horschel said. "It shows you how tough this golf course is, shows you how long the rough is."

It's the second time in the last seven weeks that Castro got off to a great start. He had a course record-tying 63 on the TPC Sawgrass for a three-shot lead at The Players Championship, and he wasn't sure which was tougher.

"They were totally different rounds," he said. "The one at Sawgrass, I hit it 3 feet eight or nine times. And the one today was more of a normal, lower round where I made some putts. It's hard to compare these two golf courses. That one was playing firm and fast. This one is just long and soft."