You've probably done it.

And the companies that specialize in golf equipment are banking on it.

Duff a shot. Pull a putt. Hit a drive a mere 150 yards with a wicked slice.

All that sends the average golfer scurrying to the nearest pro shop to buy the latest thing in titanium drivers, a super-performance golf ball or a "shank-proof" 9-iron.

"For the average golfer, it doesn't make a bit of difference," said John Aubrey Sr., owner of Aubrey's Dubbs-Dred Golf Course and Senior Tour pro.

"If a guy is shooting in the 90s, he's probably still going to shoot in the 90s with a $500 driver. He may as well get a $49 driver from Wal-Mart," he added.

Yet golf equipment is a billion-dollar industry with technological advances in the last decade that would make even NASA envious.

"Some of the stuff is amazing," Aubrey said.

In the past, golf was played with a leather ball stuffed with goose feathers.Now, some 150 years later, golf balls contain high-tech materials such as tungsten, elastomer and Surlyn.The Titleist Pro View IX is the golf ball of choice, particularly at Grove City Country Club."It's the No. 1 ball used on the pro tour," said Dante Martire, who runs the club's pro shop. "It's probably the best-performing golf ball on the market today."The average golfer's knowledge of the inner workings of a golf ball comes down to putting it on a tee and whacking it has hard as he can.But there is a method to the golf ball's madness.Manufacturers are constantly pushing the envelop on how far they can make their golf balls fly, perhaps to the detriment to the game."They have to put a stop to it," Aubrey said. "They can't make these golf courses any longer. They are running out of property. They have to start making a golf ball that doesn't fly as far. Some of these golf balls are pretty souped up."Aubrey has seen how the advances in golf ball technology have affected play. Greens that usually take three shots to reach are now taking two."But there's money in it," Aubrey said. "As long as they keep making money, they are going to make better golf balls."Technology has also affected golf clubs.Years ago, woods were actually made of wood, until titanium came on the scene. It allowed club heads to become lighter and much bigger, increasing the size of the sweet spot and reducing the margin of error.Now, the vast majority of woods are made of the high-tech metal and are paired with the equally futuristic graphite shafts.It all adds up to a massive increase in head speed, which is transferred to juiced-up golf balls, which equals greater distance - not taking into account human error, of course.But what really matters is the frequency of the shaft, a fact that eludes most casual golfers.

Aubrey can tell right away when a set of clubs "don't fit" a golfer.The frequency of his club shaft is all wrong.Most golfers achieve a shaft frequency of 240 revolutions per minute. But if the frequency isn't perfect for the swing speed of the particular golfer "everything is out of whack," Aubrey said.And that can result in poor shots."Fifty percent of this game is finding clubs that fit you," Aubrey said. "The other 50 percent is your swing. It's that simple. The average golfer doesn't have a clue."Tour pros have known this for years.At all major golf events, club manufacturers have trailers set up to help a pro fit his clubs perfectly.Aubrey said Hale Irwin goes through 50 sand wedges on a practice round to find one that fits him.Sam Snead will hit balls at the driving range and tell his caddie to take the club to his manufacturers' trailer to change the shaft of the club to find the right frequency that suits him.John and Jane Golfer don't have that luxury."The average player gets a stock set of clubs and most of the time they don't fit," Aubrey said.Aubrey said he has fitted clubs for hundreds of golfers with excellent results."If you get clubs that fit you, that's half the battle," he said. "Lessons can help the rest."But some golfers prefer to let their wallets try to fix their game.

Terry Fair of Butler is very particular about his golf equipment.He plays only Nike balls - one of more than a dozen major golf ball manufacturers.Fair, 35, won't hit a golf ball without a swoosh on it."I've been playing with a Nike ball for the last two years," Fair said. "I like the logo. It's more of a mental thing than anything, but I do notice the difference if I use a different ball."Fair said he likes the distance he gets with the Nike TI Velocity golf ball he uses regularly."For my level of play, it's a great ball," he said.Fair, who will be heading to Iraq for a one-year tour of duty soon, has more than $3,500 invested in his clubs.Adam Baldauff of Butler also has a lot invested in his.Baldauff, 34, has woods that cost $2,500 each in his bag and a $100 putter and pitching wedge.Even his bag is state-of-the art, topping out at $2,000."I'm not hitting Northwestern, if you know what I mean," Baldauff said, referring to a company that makes discount golf equipment.But Fair and Baldauff are in the minority when it comes to casual golfers.

Pete Stariat of Butler sends golf balls flying straight and true at an area driving range.The balls in his bag are discount. His clubs are basic and without frills.And that's the way he likes it."I buy whatever is on sale," Stariat said. "I'm not good enough."Stariat won't buy a dozen golf balls for $50. He believes that at his skill level, what kind of ball he buys won't make a difference."They're all basically the same," he said. "As long as they are legal and sanctioned, I'll use them."Jonathon Aglio of Butler feels the same.He and his wife, Jennifer, have taken up golf again after being on a fishing kick."I'm just a hacker," Jonathan Aglio said. "I buy whatever is reasonably priced."With all the technology out there - shaft frequencies, golf ball chemistry - it's enough to make the average golfer's head spin.

Sometimes the best strategy is no strategy at all.With all the technological advances in club heads, shafts and golf balls, and even with the gadgets and gizmos - and sometimes hypnosis - to help golfers improve their game, the results have been minimal.According to the USGA, the average golfer's handicap is 16.1. It has dropped by less than a half stroke in the last 10 years, despite the technological boom.But that's OK for most golfers. The bottom line is not their score or handicap, but their fun."I'm just out here having a good time," Aglio said. "That's all I care about."