The hobby got a lot more complicated when parallel cards, autographed inserts and half grades entered the lexicon. Nolan Ryan may only have one rookie card but Ryan Zimmerman has a few dozen.
However, to dismiss newer cards as having little or no future from an investment perspective wouldn't be accurate. Value still depends a lot on player performance, the popularity of an issue and whether you're lucky enough to score an autographed card with a low print run.
Jeff Hwang wrote a pretty well researched article on the baseball card as an investment earlier this year for the investment website, The Motley Fool.
Now, he's back with a look at modern cards, analyzing graded vs. ungraded and more, utilizing some of his own math to make some deductions.
He's fairly bullish on the current market, based on the print runs which are much smaller for many key issues than they were in the days of the Griffey rookie.
Read his analysis here.