By Saturday morning, March 19, my March Madness bracket on the New York Times website ranked sixth place among thousands of entries. You might assume from my spot on the "top scorers" list that I've watched college basketball religiously, can recite player rosters from memory, and have an inside track on predicting sports outcomes.

Nope. I just guessed.

When funds mislead you
That kind of short-term performance is easy to mistake for expertise, whether in college sports or mutual funds.

According to Morningstar, the top one-year performer at the moment is the Birmiwal Oasis (BIRMX) fund, up 197%! Its top holdings recently included Sprint Nextel (NYSE: S), Freddie Mac (NYSE: FRE), and Synovus Financial (NYSE: SNV). But if you're tempted to grab a piece of those 100%-plus returns for yourself, think twice.

With just $19 million in assets, this tiny fund has a correspondingly high fee -- a whopping 2.57% annually. Its turnover is also steep, suggesting that its managers jump in and out of various holdings with little long-term conviction. (Along the way, they're racking up commission costs and a significant tax bill.) Most importantly, you simply can't expect Birmiwal Oasis to keep posting 197% returns year after year.

I know this from experience. I once bought into the Fidelity Emerging Markets (FEMKX) fund after it gained 84% in a single year. New to investing, I assumed that the managers could turn in similar performances regularly. But the fund didn't do nearly as well the next year, prompting me to sell. With holdings such as China Mobile (NYSE: CHL), Teva Pharmaceuticals (Nasdaq: TEVA), and Petroleo Brasileiro, that same fund has gained about 86% over the past year -- but over the long haul, it hasn't been the most impressive fund in its very promising category

Don't embrace that bracket
Like my basketball predictions, some top funds' performances owe solely to luck, or to a temporary hot streak in a given sector. To get a better idea whether a fund is a one-hit wonder or a true Cinderella story, look beyond a fund's recent returns to its track record over the past five years, the past decade, or since its inception.

As for my March Madness bracket? The last time I checked, I'd fallen to 251st place.

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Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article. Sprint Nextel is a Motley Fool Inside Value selection. Ford Motor is a Motley Fool Stock Advisor pick. Petroleo Brasileiro is a Motley Fool Income Investor choice. The Fool owns shares of China Mobile. The Motley Fool is Fools writing for Fools.