When starting a baseball card collection, there are a few main factors to consider when deciding which cards to pursue. The first thing to think about is your own interests and which players, teams, or eras you most enjoy. Collecting cards that you personally connect with will make your hobby much more fun and enriching. There are also some cards that tend to hold strong value in the marketplace over long periods of time. Focusing on these blue-chip cards can help build a collection with solid long-term appreciation potential.

One category of cards that consistently maintain strong demand are rookie cards, which are a player’s first officially licensed card issued by the major card companies (Topps, Bowman, etc.). Collectors love chasing down the rookie card of their favorite star players. Some excellent rookie cards to target from the modern era (1990s-present) include Ken Griffey Jr. (Upper Deck), Chipper Jones (Topps), Derek Jeter (Topps), Mariano Rivera (Bowman), Mike Pujols (Bowman), and Bryce Harper (Bowman). For a vintage option (pre-1990), good rookie choices include Mickey Mantle (Topps), Willie Mays (Topps), Sandy Koufax (Topps), and Nolan Ryan (Topps). Mantle and Mays rookies in particular can fetch big money in high grades.

All-time great players with sustained careers of excellence also tend to produce cards with solid staying power. Stars like Babe Ruth, Ted Williams, Lou Gehrig, Joe DiMaggio, and Hank Aaron spawned multiple high-value cards across different decades thanks to their legendary playing careers and larger-than-life legacies. Modern equivalent options could be cards featuring Barry Bonds, Albert Pujols, Miguel Cabrera, and Clayton Kershaw. Autograph and relic cards from these all-timers hold especially strong appeal.

For team sets, pursuing complete runs of the classic vintage sets like Topps (full runs from 1952-1980 in particular), Topps Traded and Flagship parallels, and Topps Update cards with current stars offer a balance of historical significance and modern relevance. Full sets become more difficult to assemble the further back you go, but are prized by set collectors. Targeting full runs of the more recent Topps flagship sets provides a solid foundation while being reasonably attainable.

Error and variation cards that debut flaws or unique production runs have also demonstrated an ability to increase substantially in value with time. Examples include the infamous 1969 Topps Reggie Jackson error card, 1990 Topps Griffey error, or 2011 Topps Update Bryce Harper autograph variation. These anomalous pieces intrigue collectors and command strong auction prices when high-grade examples surface decades later.

Grading company slabbed cards in Mint condition (9-10 grade on the 10-point scale) hold a clear advantage over raw, ungraded cards and generate the most collector and investor interest. The cost to professionally grade cards through services like PSA or BGS can add up quickly. For highest returns, focusing grading submissions on the true blue-chip vintage and modern rookie options makes the most sense financially. Lower population 1950s+ era cards in pristine condition frequently receive Excellent/Gem ratings are also quite desireable.

For a collection with strength, stability, and growth potential – focus on vintage and modern rookie cards of all-time great players, full sets of classic Topps Flagship and Traded sets, high-grade error and variation cards, and autograph/relic inserts of franchise players. Tying your pursuits to your favorite teams and eras help keep the hobby fun while these categories of cards have proven they can hold strong resale value for dedicated collectors over decades. With patience and a mid-to-long term outlook, building a strategic baseball card portfolio is feasible and offers an engaging avenue for appreciation of the game’s rich history.