"The Guy," back in my day, was named Joe Granville.

With his slick black hair and dark suits, Granville looked the part of an insider who knew the stock market, but pulled back the curtains so the "little guy" could get some, too. One day Granville said, "Sell everything," and the stock market promptly took a sharp fall -- for a day or so. His act worked for maybe a couple of years, until he gave enough advice, made enough predictions so that the bad ones stacked up. People lost interest, and finally wrote Granville off as a crank.

Today "The Guy" is Jim Cramer.

Cramer hosts CNBC's "Mad Money." During a recent stock market sell-off, the stock analyst/investment adviser pronounced the situation "Armageddon."

According to the financial publication Barron's, "Over the past two years, viewers holding Cramer's stocks would be up 12 percent while the Dow rose 22 percent and the S&P 500 16 percent, according to a record of 1,300 of the CNBC star's Buy recommendations compiled by YourMoneyWatch.com, a website run by a retired stock analyst and loyal Cramer-watcher.

"We also looked at a database of Cramer's 'Mad Money' picks maintained by his website, TheStreet.com. It covers only the past six months, but includes an astounding 3,458 stocks -- Buys mainly, punctuated by some Sells. These picks were flat to down in relation to the market. Count commissions and you would have been much better off in an index fund that simply tracks the market."

This raises an age-old question. If "The Guy" knows everything -- when to buy, when to sell -- why not simply park yourself in front of your computer and grow richer?

When I was about 9 or 10, my mom took me, for the first time, to the racetrack. Near the entrance stood several guys standing behind podiums. They sold "tout" sheets. For a price, you could buy a list of horses -- expected to win, come in second or come in third -- for each race. "Mom," I said, "why don't we buy one of the sheets?" She looked at me and said, "If they know so much, why aren't they inside betting?"

The stock market "crashed" about 20 years ago. Just before this downturn, in a newsletter to her clients, an analyst with one of the major investment firms "predicted" the sell-off. She immediately became "The Guy." Networks elbowed each other to have her on. Pretty, with curly red hair, she made for good television and offered up detailed predictions.

Her advice after the sell-off? Stay out of the markets. The stock market, she said, now resembled a house of horrors, Dante's Inferno, a place to enter only at one's peril. It turned out, in retrospect, that the sell-off presented an excellent buying opportunity. Yet during interview after interview, she gave the opposite advice. As with Granville, enough wrong predictions stacked up, and she lost credibility and faded. The quest began anew for "The Guy." Continued...