Even the best mutual-fund manager can have a lousy 12 months.

In an unusual development, several top managers in the large-company "value" category posted lousy returns last year, despite their impressive long-term records. The managers were experienced, well-respected and in some cases quite famous in investing circles for their ability to deliver consistently impressive results. Yet last year the only thing consistent about them was their inability to do so.

"We're kind of scratching our heads," says Phillip Davidson, a manager for the $3.8 billion American Century Equity Income fund in Kansas City, Mo., which ranked in the top 2 percent of the category over the past 10 years but was in the 87th percentile, near the bottom, for the 12 months through the end of November, the latest data available, according to Morningstar Inc. "Everything that worked for the last 10 years worked the least amount this year."

It was a tricky year for large-capitalization value stocks. Money managers in this category often seek out undervalued gems among large companies through in-depth financial analysis, rather than by trying to predict macroeconomic trends such as rising oil prices. This helps explain why many top managers missed out on the booming energy sector -- soaring oil prices were terrific for energy-company stocks last year -- and instead opted for consumer and financial-services picks that didn't always pan out.

Some common favorites that soured were Wal-Mart Stores Inc., Liberty Media Corp. and General Motors Corp. Popular picks in the beverage, health-care, financial-services and media sectors also stalled, like Anheuser-Busch Cos. and Fannie Mae.

Still, top managers generally don't change their fundamental strategies given mediocre short-term results and most see potential for an upswing in their portfolio in coming months.

At the $6.2 billion Oakmark Select Fund in Chicago, a combination of weak media picks and missed energy opportunities put well-known manager Bill Nygren in the 76th percentile. The fund returned 6.33 percent for the 12 months through November but ranks in the top 4 percent of the category for the five-year period, according to Morningstar.

In his third-quarter letter to shareholders, Mr. Nygren noted that, "typically when our performance lags, it is because we made several large fundamental errors." Last year though, only vaccine-maker Chiron Corp. declined by more than 10 percent in the portfolio, and the stock was eventually sold.

Mr. Nygren says his tendency to favor companies with strong management teams and clear strategies didn't deliver the results he had hoped for. Holdings like Xerox Corp. and H&R Block Inc. stayed flat, while the fund's overweight position in media stocks like Viacom Inc., Time Warner Inc. and Liberty Media pulled performance down.

Oakmark Select's only energy pick was Burlington Resources Inc., and there were no electric-utility stocks in the portfolio, in part because "it was hard to get excited about the specific advantages of utilities or their management," Mr. Nygren says.

Similarly, Brian Rogers, manager of the $21 billion assets T. Rowe Price Equity Income Fund in Baltimore, says anyone who hadn't invested in those sectors found it hard to beat the market.

"If I'd had another 5 percent in energy, we wouldn't be having this conversation," he says.

The fund fell to the 55th percentile of its category with 7.96 percent in average returns for the 12 months through November, but ranked in the top quartile over the past 10 years, according to Morningstar.

"In essence every sale was a bad sale," says Mr. Rogers, referring to how the fund cut back on energy stocks and invested in health-care, media and consumer-products shares last year. Media and entertainment was "a disappointing place to be" despite its long-term potential, he says.

At the Yacktman Fund in Austin, Texas, holdings like Coca-Cola Co. and Kraft Foods Inc. were some lackluster stocks in the portfolio. The $456 million fund is in the bottom 96th percentile over the past year through November with 2.79 percent in returns but ranked in the top 16 percent over the past decade.

Short-term performance doesn't worry manager Donald Yacktman, though, given that two other down years in the fund's 14-year history "were followed by periods of brilliance."

Sometimes specific fund parameters held performance back. The American Century fund, for example, seeks to create a portfolio with a dividend yield two percentage points above that of the Standard & Poor's 500-stock index. Dividend yield is the ratio of per-share dividend payout over the past 12 months to current stock price.

To help meet its yield targets, the fund keeps about 30 percent of holdings parked in instruments like convertible bonds, which were weak performers last year. Mr. Davidson says his team struggled to find large companies paying out as much as they were looking for. While holdings like Commerce Bancshares Inc. did well, others like Kraft and Bank of America Corp. declined. The fund also struggled to find specific energy stocks that fit its dividend-hungry criteria.

"Our strategy isn't broken," he says. "But it's been hard to find great opportunities."

Other laggards last year included the $6.7 billion Clipper Fund, which is managed from New York and ranks in the top 3 percent of its category over the 10-year period with 12.78 percent annualized returns, but in the bottom 98th percentile over the past year through November, and the $8.7 billion Longleaf Partners Fund in Memphis, Tenn., a large-cap blend fund that fell to the 80th percentile of its category last year through November but is in the fourth percentile over the past 10 years. Despite the results, Longleaf's managers wrote in their third-quarter report "we are more optimistic about our portfolios than we have been in over two years" because they have made some promising new investments recently like Dell Inc. A Longleaf representative declined to comment and a Clipper fund manager was unavailable to comment.