If you haven't heard of Legg Mason (NYSE:LM) mutual fund manager Bill Miller, it's high time you did. He's well known in the financial world for having led his Legg Mason Value Trust (FUND:LMVTX) to S&P 500-beating results for a record-setting 15 consecutive years. It's hard to argue with success like that, but that's just what Roy Weitz did recently, at his fundalarm.com website.

Weitz wrote that the fund "has underperformed its benchmark for the past 12 months, three years, and five years, and it's now classified as a 3-ALARM fund." Yikes!

He went on to explain: "What we're dealing with here is an issue of timing ... when you look at Legg Mason Value for periods other than full years, its overall performance can be considerably less than legendary." He added that, "to his credit, Bill Miller has repeatedly made this same point."

Here's what's going on: During the 2005 calendar year, the fund beat the S&P 500 by 0.4%, but between August 1, 2005 and July 31, 2006, the index beat the fund by 11.4%. Weitz provided data for several years, and in some the index comes out ahead, while in others, Miller's fund does.

Weitz concludes: "Calendar-year track records, like Miller's, are curiosities, which relate only coincidentally to the one investment goal that really matters: Having the most possible money in your account at the end of a given time period." With this, I heartily agree. Buying into a fund solely because of its calendar-year records isn't the best idea.

Instead, look at the long-term overall record (Miller's 10-year annualized gain is a respectable 13%, though it's less impressive over shorter periods). Examine the fund's recent top holdings and see whether they're the kinds of investments you'd like to own. (Miller's top holdings recently included Amazon.com (NASDAQ:AMZN), Google (NASDAQ:GOOG), Sears Holdings (NASDAQ:SHLD), Eastman Kodak (NYSE:EK), and Home Depot (NYSE:HD).)

Looking at a fund's holdings can also give you insight into its performance and prospects. Miller is holding some clearly out-of-favor companies, such as Home Depot and Kodak (among others), and they may not contribute a lot to the fund's bottom line for a while.

If you're looking for a good mutual fund, go ahead and consider Miller's fund. But consider others as well. We'd love to introduce you to some top-notch funds via our Champion Funds newsletter, which delivers recommendations and updates each month. Together, the picks of our analyst Shannon Zimmerman have more than doubled the market's return (as of the last time I checked), gaining an average of 19% versus 11% in the same time period. Try the newsletter for free and you'll be able to see all his picks and how well they've done.

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Longtime Fool contributor Selena Maranjian owns shares of Amazon.com and Home Depot. The Fool has an ironclad disclosure policy.