Tough opening day for the defending World Series champ Phillies on Sunday: The Atlanta Braves cooled the Phillies' jets, beating them 4-1. And in Baltimore on Monday, the Yankees' brand new, high-paid talent -- in the harsh glare of the spotlight -- couldn't stave off an opening day loss to the Orioles, 10-5.

Everyone feels like they've got a lot to live up to. But now that opening-day jitters are behind them, everyone can relax and play some ball.

I don't get jitters when picking stocks for my deep-in-the-money options trading system. You can follow my system -- which has a win record of 99-1 -- through a subscription to my Nails on the Numbers newsletter. One of my key measures in evaluating a pick is its cash flow.

Operating cash flow is reported in big, round numbers that need some context to see how good they really are. So today, let's look at the operating cash flow ratio, which is a company's operating cash flow divided by its current liabilities. What this gives us is a measure of how well a stock's cash flow covers its current liabilities.

The higher the ratio, the better. But few companies can approach a ratio of 1.0. Rather, many have cash-flow ratios that are near zero. But let's look at some cash-flow winners. Pfizer ( PFE), which won for me in October, had operating cash flow of $5.97 billion in December. With current liabilities of $27 billion, the pharmaceuticals giant had an operating cash-flow-to-current liabilities ratio of 0.22 that quarter. That is up from a ratio of 0.17 for the same quarter of the prior year.

My frequent pick and winner Microsoft ( MSFT) had a good ratio of 0.24 in December. On March 26, Microsoft rang the bell for me for the fourth time, after 13 days in play. Not uncommon for profitable companies is the December ratio of 0.08 for General Dynamics ( GD) -- a recent pick.

Not surprisingly, 2008 was a banner cash year for oil companies, giving them ratios higher than most industries. One of my recent picks, Occidental Petroleum ( OXY) had operating cash flow of $2.52 billion for the December quarter. With current liabilities of $6.1 billion, its ratio was 0.41 - an improvement from 0.39 for the same quarter of 2007.

Among other recent oil-industry stocks I've picked, Transocean ( RIG) had a cash-flow-to-current liabilities ratio of 0.44 in December.

One oil industry firm did manage to pull off a cash-flow ratio in December that was greater than 1.0. Diamond Offshore Drilling ( DO) had a ratio of 1.14 on cash flow of $580.4 million and revenue of $3.5 billion. It currently trades at just 6.6 times 2009 earnings per share.

Oil is not the only industry to generate cash-flow winners. Aircraft manufacturer Lockheed Martin's ( LMT) cash-flow-to-current-liabilities ratio was a sterling 0.42.

At the time of publication, Dykstra had no positions in stocks mentioned.

Nicknamed 'Nails' for his tough style of play, Lenny is a former Major League Baseball player for the 1986 World Champions, New York Mets and the 1993 National League Champions, Philadelphia Phillies. A three time All-Star as a ballplayer, Lenny now serves as president for several privately held businesses in Southern California. He is the founder of The Players Club; it has been his desire to give back to the sport that gave him early successes in life by teaching athletes how to invest and protect their incomes. He currently manages his own portfolio and writes an investment strategy column for TheStreet.com, and is featured regularly on CNBC and other cable news shows. Lenny was selected as OverTime Magazine's 2006-2007 "Entrepreneur of the Year."

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