There are many factors to consider when choosing baseball cards to purchase as an investment or collection. The most important cards to focus on are those of star players, especially those who had long and productive careers as well as playoff and championship success. Investing in rookie cards of future Hall of Famers who went on to have incredible careers can provide great returns. It’s impossible to predict the future, so it’s best to focus on players with a proven track record.

Some specific players and sets I would recommend looking into include cards of legendary stars from the 1940s-1980s before the massive expansion of the hobby. Stars like Mickey Mantle, Ted Williams, Willie Mays, Hank Aaron and others from that era tend to hold their value very well. Their rookie cards or early career cards that were printed in much lower numbers are quite scarce and desirable among collectors decades later.

For the modern era, rookie cards or early RCs of all-time greats like Ken Griffey Jr, Chipper Jones, Derek Jeter, Mariano Rivera, Albert Pujols and others would be wise purchases. Look for high-grade copies of their Topps rookie cards, Bowman Chrome rookie refractor parallels, or limited edition special release cards from that time in pristine condition.

Another option is to focus on stars from championship teams who captured World Series titles, MVP awards or had epic postseason performances. Cards of players like Babe Ruth from the 1920s Yankees dynasty, Joe DiMaggio, players from the 1950s Yankees like Mickey Mantle and Whitey Ford, members of the 1970s-90s Oakland A’s dynasty like Reggie Jackson and Rollie Fingers, stars from the 1990s-2000s Yankees three peat teams like Jorge Posada and Andy Pettitte hold cache.

Similarly, cards featuring iconic individual playoff moments in history could retain value nicely as those authenticated pieces of history. Examples might include cards featuring Kirk Gibson’s 1988 World Series walk-off home run, Joe Carter’s 1993 World Series game winner or cards highlighting David Freese’s 2011 World Series MVP performance.

For the truly high-end, rare vintage cards in pristine grades of the all-time greatest players could yield enormous returns. Realistically though, most collectors will have to settle for high-grade modern rookie cards or authenticated memorabilia cards of current stars. But with patience and a keen eye, even modest investments can grow substantially over time.

Some specific sets, years and paraphernalia to consider targeting include:

1952 Topps – High-grade examples of Mickey Mantle’s amazing rookie season. Very limited print run makes PSA/BGS 9+ copies extremely scarce.

1957 Topps – Willie Mays’ impressive career was already underway but high-grade examples command big money.

1968 Topps – Probably the most iconic set of the 1960s and early trading card boom era before mass production. High-grade Hall of Famers are pricey.

1974 Topps – First cards featuring color photographs instead of illustrations. Marked transition to modern design that collectors love.

1979 Topps Traded – Extremely early Derek Jeter rookie still widely sought after today.

1987 Topps – Tall boys featuring the rookie cards of Tom Glavine, Greg Maddux and David Justice from Atlanta’s future dynasty years.

1989 Upper Deck Ken Griffey Jr. rookie – Highly recognized as one of the most iconic and valuable modern rookie cards. Early serial numbered parallels very scarce.

1992 Bowman Derek Jeter rookie – Much lower printed run than Topps makes high-grade copies rare and pricey.

2001 Topps Albert Pujols rookie – One of the last affordable rookie cards of such an all-time great slugger before prices skyrocketed.

2007 Bowman Chrome Draft Kris Bryant – Available right as his career began taking off leading to huge returns for early buyers.

Certified autograph cards from the 1960s of all-time legends like Mickey Mantle, Ted Williams etc in impeccable condition could set back investors six figures or more due to extreme rarity.

Signed game-worn jerseys, bats, balls or other memorabilia pieces authenticated with legitimate provenance pertaining to all-time great postseason performances could earn handsome returns as display pieces.

While sports cards should always be seen as somewhat speculative long-term investments prone to boom/bust cycles, focusing on star players of the past and present from proven championship winning franchises offers the best chances for growth over the years. Diversifying an overall portfolio among several decades, sets, rookies and stars helps mitigate risk. And obtaining high-quality, well-centering grading when possible further serves to maximize future values for serious collectors. Starting small and dollar-cost averaging into positions gradually over time is also a smart approach for building positions in top cards before their prices potentially escalate much higher in the coming decades. With patience, research and discipline, a baseball card collection can offer significant portfolio returns alongside enjoyment for any true fan of America’s pastime.

When investing in baseball cards, the smartest approach is focusing on the all-time greatest players, especially their early career and rookie cards from before the modern era. Established stars from championship teams whose successes became a permanent part of baseball history and lore provide the best chances at long-term appreciation. Combining premium condition, desirable parallels and autograph/memorabilia elements can maximize future values when buying iconic cards as financial investments. With due diligence selecting proven performers amidst ever-changing markets, a baseball card collection assembled intelligently over the years can reward collectors for decades to come.