Congratulations, U.S. Ryder Cup fans. You're making "Caddyshack" look like a documentary.

On the kind of day that Hazeltine National members have been dreaming about for years, the sun shone, the Americans played brilliantly, tens of thousands crowded around every hole in play and a not-small-enough percentage of fans made fools of themselves.

One yelled something too disgusting to print at Rory McIlroy. Another yelled while Henrik Stenson was addressing a putt. Another did the same to Danny Willett.

On Friday, fans yelled at Willett's mother about a post written by Danny's brother that chastised American fans for being drunken louts. After the past two days, that post could be expanded into series of hardback books.

It would be convenient to pin the troubles on a handful of overserved patrons, but the general tenor Saturday afternoon was nasty.

Golf is not supposed to be rude. Even the Ryder Cup should be about intense but respectful competition. This event is compelling enough to stand on its own.

If you want to get drunk and scream stupidly at athletes, tuck some bail money into your sock and attend an NFL game.

"I think there's been some boundaries overstepped," McIlroy said. "Not on my side. It's been a tough crowd and … you just need to concentrate. I let it get to me a couple of times out there, and I probably shouldn't have. But it's tough. It's long days, it's 4:30 wake-up calls, you're playing a lot of golf, every now and again you're going to let it get to you, especially when emotions are running so high."

I walked six holes with McIlroy. I heard three unprintable screams; a half-dozen smarmy chants of his name; loud cheers every time he hit a bad shot or missed a putt; chants of his ex-girlfriend's name; and similar treatment of playing partner Thomas Pieters.

Both players heard jeers and taunts as they stood over putts.

After McIlroy hit his tee shot on 16, he kicked at the grass, clearly upset. When his team won a hole early in the match, he screamed, "Come on!" or pumped his fists. By the end of the day, he sounded exhausted.

"I'm going to try to get a good night sleep and I'm going to take a couple of Advil for this headache I have after listening to the loudness over the last few days, and get ready for tomorrow," he said.

On the 11th hole, Stenson got upset with a fan, and American vice captain Bubba Watson stepped in.

Of course, when Watson tried to calm someone yelling at Willett on Friday, a fan yelled something vulgar at Watson. Team Europe vice captain Ian Poulter tried to calm a fan on the fourth hole, saying, "Show some respect."

On the seventh hole Saturday, a fan yelled something at McIlroy that caused McIlroy to approach him.

"Someone just said a few derogatory things I thought was over the line," McIlroy said. "I tried to get him removed. I'm not sure whether he was removed or not [he was].

"These things happen. It's golf at the end of the day. You try to maintain the utmost respect for who you're playing and who you're supporting.

"That particular guy was obviously in the very, very, very small minority and just took it a bit too far."

An informal poll of golf writers indicated that the Ryder Cup hasn't experienced this level of ugliness since 1999, when the Americans won with a stunning comeback at Brookline, while trampling greens with massive and premature celebrations.

American players haven't behaved so poorly since. American fans must have lost the memo.

The attempts to break McIlroy's concentration aren't just wrongheaded, they're ineffective. He has won his past three matches. If the crowd had left him alone, the U.S. might have the Cup all but wrapped up.

Instead, McIlroy and his teammates will enter Sunday's singles matches unified against a common enemy: the fans who are embarrassing the home country.

Jim Souhan's podcast can be heard at MalePatternPodcasts.com. On Twitter: @SouhanStrib. • jsouhan@startribune.com