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Warren Buffett, chairman and chief executive officer of Berkshire Hathaway Inc. speaks to members of the media outside the Bridge Center in Omaha, Nebraska, U.S.

When I first saw the headline Breaking Buffett: The Oracle has underperformed on CNBC.com, I was skeptical.

After years of following him for the Buffett Watch blog, I’ve seen quite a few Has Buffett Lost His Touch? stories and posts over the years, like these from 2008. 2009. 2010. 2011. 2012 and 2013 .

In 2009, investor Doug Kass saw the end of Buffett and CNBC’s Jim Cramer strongly questioned Buffett’s call tobuy American stocks near the height of the credit crisis.

Thursday’s Breaking Buffett piece detailed an analysis by Bespoke Investment Group showing Berkshire’s top 10 stock holdings are up an average of 0.7 percent for the third quarter, lagging the benchmark S&P 500 index’s 4.9 percent gain.

But that’s just six weeks, an insignificant time span in Buffett’s long-term investment world view. I thought that stepping back a bit would produce a different picture.

So I looked at those stocks year-to-date, and found, again, they underperformed the S&P. It’s closer, but Berkshire’s top 10 averaged a 14.9 percent gain vs the S&P’s 18.2 percent advance. Weighting the average by the market value of the positions in Berkshire’s portfolio reduced its gain to 13.7 percent.

Over 12 full months, the same story. Berkshire’s stocks are up 17.7 percent (just 12.7 percent weighted) while the S&P is up 20 percent.

It’s true. Buffett’s stocks have been falling behind the market.

Three of Berkshire’s major holdings, Wells Fargo. Coca-Cola and American Express. have been in the portfolio for years. Wells and AmEx have been spectacular performers over the past twelve months as financials rebounded from the credit crisis. Coke has been roughly flat. (Over the longer run, of course, they’ve helped make him one of the world’s richest billionaires.)

It’s Buffett’s most recent big stock pick that’s trailing the pack.

IBM is up 7.2 percent since the end of 2011’s third quarter, when Buffett finished accumulating the bulk of what is now a $12.6 billion stake. Not bad, but well short of the S&P’s 49 percent surge over the same period.

Even by Buffett’s favorite metric, book value. a measurement of the value of assets on a company’s balance sheet, Berkshire is lagging the S&P.

In his annual letter to shareholders last March, Buffett was disappointed that Berkshire’s per-share book value increase of 14.4 percent in 2012 was less than the S&P index’s 16 percent increase. A subpar year, he said, even though it was a $24 billion gain.

It’s our job to increase intrinsic business value — for which we use book value as a significantly understated proxy — at a faster rate than the market gains of the S&P, he wrote, but predicted Berkshire would beat the S&P by only a small margin over time, in part due to its large size.

Berkshire is beating the S&P by one important measure that directly affects its investors: stock price. Berkshire’s Class B stock is up 30 percent year-to-date, compared to the S&P’s 18.2 percent gain. For the last twelve months, Berkshire is ahead 37.2 percent to 20 percent.

Berkshire’s shares, of course, represent a lot more than just its own stock holdings, and business has been good for many of the subsidiaries, including Buffett’s 2010 acquisition, Burlington Northern Santa Fe.

So, perhaps Buffett hasn’t entirely lost his touch, but there’s no denying his stock picks have been below par, at least lately.

Even he acknowledged that in his March shareholders letter.

After praising Berkshire’s two new portfolio managers for beating the S&P by double-digit margins in 2012, Buffett used very small type to add, They left me in the dust as well.