I'll level with you ...

I enjoy investing -- but I love watching football.

Now that the season is over, it's time to turn my attention to stocks. That doesn't mean we can't talk about football, though. After all, there are plenty of parallels between pigskin and profitable investing.

It's all about the "O"
Patriots fan or not, watching Tom Brady march his troops down the field is pretty darn inspiring. It's also a big part of why the Patriots were almost the first 19-0 team in NFL history (quite the upset, huh?).

But you know what? Watching companies that grow like wildfire and pump out profits in the process can be just as exhilarating -- particularly when you're a shareholder. And last year was prime time for these "offensive" stocks.

But then 2008 hit -- harder than Roy Williams
All of the sudden, the bears finally got to investors, and everyone went from cheering on the offense to whispering the dreaded "R word." Just like that, 2007's big winners turned more frigid than Lambeau Field during the Ice Bowl:

Stock

Gain in 2007

Loss, Year to Date

Apple (Nasdaq: AAPL)

134%

33%

Google (Nasdaq: GOOG)

50%

25%

Intuitive Surgical (Nasdaq: ISRG)

237%

5%

Research In Motion (Nasdaq: RIMM)

166%

19%

Now, if "offensive stocks" were a topic on tomorrow's sports talk show, there's no doubt there would be a fight to the death over whether now is the time to (A) throw in the towel, or (B) go value shopping.

While the market still looks fairly volatile and there are no guarantees in the short term, don't forget that history is on the side of the second approach. Not to mention, when it comes to investing, prematurely throwing in the towel can end up costing you a fortune.

Going for it on fourth down takes guts
But sometimes it pays off huge. Take, for example, the gutsy decision of Packers coach Mike McCarthy in a recent playoff game to "dance with who brung him."

In case you missed it, Packers running back Ryan Grant fumbled two of his first three carries and virtually handed the Seahawks an immediate two-touchdown lead. Yet despite falling into a major hole before he could even blink, Coach McCarthy neither panicked nor let his emotions make decisions for him.

According to McCarthy, "[Grant] was a big part of the game plan. I never gave it a thought [to bench him], never one thought. We stuck with the game plan."

If I were McCarthy, I would have yanked Grant and never looked back. But that's why I'm not a professional football coach -- Grant ended up leading the Packers to victory with two touchdowns and a record 201 yards rushing.

It's also a pretty good indication of how my emotions could influence my investment decisions -- and that could spell disaster.

This is money, not football
For the sake of our long-term financial well-being, we need to avoid the temptation of joining the panicked rush for the exits.

Instead, we need to revisit each position in our portfolio. If our investment thesis is no longer intact, we need to consider selling. But if it is, we need to consider buying more -- while the stock is still on sale.

As Motley Fool co-founder Tom Gardner says, "The best time to invest was yesterday, and the second-best time is today." And if you do decide to go shopping, don't forget ...

The best offense is a good defense
Every Apple store I've seen in the past three months has been absolutely packed, and it seems like each day someone I know gets a new iPod, iPhone, or MacBook. Yet the numbers indicate that consumer spending is declining, and that may well slow offensive stocks down for a while.

So it's important to keep an eye out for companies that can continue to pull in revenue no matter how bad the economy gets. That means looking for companies that sell things like cigarettes, medicines, and toiletries.

These might seem like boring businesses that don't have much room for innovation or breakout growth, but these "defensive" stocks tend to do well even when the economy slows.

Not to mention, defense wins championships
Pittsburgh's infamous Steel Curtain defense helped the Steelers become a dynasty in the 1970s -- and the Giants' defense won them the Super Bowl last night.

Similarly, having a handful of great defensive stocks in your portfolio over the past two decades would have carried you to great financial success. And don't forget, many of them pay nice dividends:

Stock

$10,000 Invested 20 Years Ago Would Now Be Worth ...

Current Yield

Altria (NYSE: MO)

$338,295

4.0%

Pfizer (NYSE: PFE)

$173,455

5.5%

Procter & Gamble (NYSE: PG)

$200,151

2.1%

Returns are with all dividends re-invested.

If you had invested just $10,000 in each of these stocks in 1988, you'd be sitting on more than $700,000 right now. Not bad for "defensive" stocks, huh?

But would they win the Super Bowl of stocks?
Truth be told, even if there were a Super Bowl of stocks, plowing all of your money into the stock that looked poised to win it would be a huge mistake.

As investors have found out over the past few weeks, anything can happen in the stock market. It's important to remember that stocks trade in a marketplace where buyers and sellers are extremely fickle. What's working one day might not work the next.

That's why it's important to spread your money out over a wide variety of stocks. You should own some offense, some defense, some large caps, some small caps, and even some international stocks. But whatever you do, make sure you own quality.

Unlike football, investing isn't about putting it all on the line to win one game. Instead, it's about building a strong, balanced portfolio that can consistently lead you to winning returns over the long haul.

David and Tom Gardner started Motley Fool Stock Advisor in the midst of a ferocious bear market with the goal of leading investors to stocks that would build their wealth over the long haul -- through good markets and bad. On average, the stocks they've recommended have returned investors 40 percentage points more than a like amount invested in the S&P 500.

If you'd like to learn more, I invite you to take a free 30-day guest pass to Stock Advisor. You'll be able to see all of David and Tom's recommendations, including their two top picks for your new money now.

I know it's not as exciting as tickets to the Super Bowl, but it could help you to become a better investor. To take me up on this no-obligation offer, simply click here.

Fool contributor Austin Edwards is a lifelong Packers fan and really wishes that interception from Brett Favre hadn't happened. He also owns shares of Apple, Google, Intuitive Surgical, and Altria. Intuitive Surgical is a Motley Fool Rule Breakers pick, and Pfizer is an Inside Value pick. The Fool's disclosure policy is less forgiving than Tom Coughlin after a missed field-goal attempt.