It was tough luck in Torino last week when Lindsey Jacobellis blew her chance at gold. The young American snowboarder had a wide lead and inexplicably went for a hotdog move just meters before the finish line. She stumbled. She fell behind. She had to settle for silver.

Some will argue that snowboarding is all about flair. If you're not cocky, they say, you're doing the new Olympic sport a major disservice. Maybe so, but the moment that Jacobellis mishandled her board, Leon Lett finally got a good night's sleep.

You probably remember Lett. As a defensive tackle for the Dallas Cowboys, he was a tenacious defender on a great football team. Then came Super Bowl XXVII. He recovered a fumble and darted for what should have been an easy score. Then he slowed down and started showboating -- just long enough for Buffalo's Don Beebe to slap the ball out of his hands. No score for Lett. From touchdown to touchback, it was Buffalo's ball at the 20.

Lett kept Jacobellis' seat warm for 13 years. Let's see how long it takes for Lindsey's replacement shows up.

Then again, it's not fair to knock gifted athletes like Lett and Jacobellis. They may have given us bloopers that will last a lifetime, but they also fared pretty darn well despite the hiccups. Lett still walked away from that gridiron contest with a Super Bowl ring, and Jacobellis still finished second, taking home some pretty snazzy hardware.

Some companies aren't that lucky. Some market leaders celebrate too early or misjudge how quickly the competition is gaining behind them. They often pay dearly for that hubris. There's no ring, medal, or trophy for stocks that let arrogance get in the way of enhancing shareholder returns.

Objects in the mirror are closer than they appear
Hewlett-Packard
's (NYSE:HPQ) ouster of CEO Carly Fiorina wasn't the printing and computing giant's finest hour. Critics pointed to Fiorina's unpopular move of acquiring troubled PC maker Compaq as the biggest reason for her downfall.

Maybe. I would argue, though, that HP's biggest tactical blunder came in January 2004, when the company decided to team up with Apple Computer (NASDAQ:AAPL) to sell its own brand of iPod players. At that point, Apple had moved just two million iPods, with half of those going to the Apple computing faithful. As part of the deal, HP helped open up the market for Apple by bundling the company's iTunes software on HP systems and flooding the market with even more proprietary iPod players.

HP probably felt it was doing the right thing at the time. Apple had a rabid following, but it was a narrow niche, commanding a mere 3% of the computing industry's market share. HP took a look back, saw that Apple was way behind, and figured that it was safe to forge a deal with a slumbering predator.

No, Apple hasn't overtaken HP. However, just as HP eventually gave up the pole position in the PC industry to Dell (NASDAQ:DELL), we now see Apple producing higher sales volume in the computing space than former bronze medallist Gateway (NYSE:GTW). Dell and Gateway can at least claim to have done their part to try to keep Apple out. They rolled out their own players, and they just weren't interested in selling you an iPod. HP loaned Apple a doorstop, and Apple kicked the door down.

The million-man silent march
Behind every disruptive technology, there's a sector behemoth living in denial. That's probably the best way to describe Blockbuster (NYSE:BBI). Just a few years ago, CEO John Antioco would dismiss conference-call questions about Netflix (NASDAQ:NFLX). Antioco mistakenly believed that most movie buffs would prefer to make a trip to the video store than wait for the next day's mail.

Blockbuster wasn't entirely asleep at the wheel, though. As Netflix continued to grow, Blockbuster quietly launched a service called filmcaddy.com. When Netflix landed its millionth subscriber, Wall Street was expecting a more ramped-up response from Blockbuster in the spring of 2003. It didn't happen. A Motley Fool Radio Showinterview later that summer also had Antioco dismissing Netflix as little more than "an alternative for people who want to go online and who like to plan their movie time ahead."

The company kept tapping the snooze bar until it was too late. A year later, Netflix had doubled its subscriber base, and Antioco finally took the threat seriously.

"We can't continue to allow our customers to erode away from us," Antioco said in the summer of 2004 as Netflix lapped the two-million-subscriber mark. "We are not going to ignore these folks." But the decision to wait until its rival had a couple million paying customers and a tailwind of momentum continues to cost Blockbuster dearly.

Amazon.com (NASDAQ:AMZN) took a smarter approach. Sensing that Netflix was cleaning house in the United States, Amazon decided to launch its DVD rental service in the United Kingdom -- a market it was intimately familiar with, far from Netflix's stomping grounds.

Jack of all tirades
If you get a chance this week, take a look at your stock holdings. If you happen to own a market leader, how far behind is the competition? Are any of the rivals doing anything different that may pose a threat to your investment?

Don't take the exercise lightly. You wouldn't want your stocks to make Jacobellis' mistake. David and Tom Gardner love to pick winning stocks for their Motley Fool Stock Advisor research newsletter subscribers, but they also enjoy keeping abreast of how their past picks are doing, to make sure that they're not hotdoggin' their way out of contention.

David and Tom may single out stocks that they really like every month -- Dell, Amazon.com, and Netflix happen to be past selections -- but they're also willing to recommend that readers take their profits and close out their positions on a previous recommendation if they feel that its climate is changing.

It's worked pretty well for David and Tom, with the average pick up a sharp 59%. That's far more than the 21% average gain returned by the S&P 500 in that time. It's why you can probably learn a thing or two about growing winners -- and pruning away underperformers, when necessary -- through a newsletter subscription or even a free 30-day trial run.

Stay focused, but always respect the footsteps behind you. Don't let up until you're on the other side of the finish line.

Longtime Fool contributor Rick Munarriz still thinks that Jacobellis should wear her medal proudly. Lett certainly isn't hiding that ring. Rick does own shares in Netflix. T he Fool has a disclosure policy. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.