The value of a baseball card can vary significantly depending on many factors like the player, the year it was produced, its physical condition, and more. Older cards and cards featuring star players tend to be worth the most. Some key things that influence a card’s value include:

Player – Cards featuring legendary players that had long, successful careers will usually be worth more than players with short careers. Stars like Babe Ruth, Mickey Mantle, Hank Aaron, and more recent stars like Mike Trout can add significant value. Rare rookie cards of future Hall of Famers can be extremely valuable.

Year – Older cards from the early 20th century up until the 1980s are usually more valuable since fewer survive in good condition today. The very first baseball cards from the late 1800s can be worth tens or even hundreds of thousands due to their rarity and historical significance. Cards from the 1950s and 1960s Organizational Era are also quite collectible.

Condition – A card’s physical condition, often rated on a 1-10 scale, has a huge impact on worth. Near mint to mint condition cards from the pre-war era could be worth 10x or more than those in poor shape. Even seemingly minor defects like edge wear, corners that are slightly rounded, or small creases can significantly reduce value. Pristine cards in encapsulated holders maintain their condition and value best.

Rarity – Parallel to condition is rarity. Some early 20th century cards and specialty subsets were produced in very small numbers which makes high grade specimens incredibly scarce and valuable. Examples include the famous 1909-11 T206 baseball card set, the 1914 Cracker Jack cards, and early oddball issues like 1933 Goudey and other specialty sets.

Authenticity – An authentic, properly graded card will hold its value but counterfeits have no collectible value. As card values have risen, so has the prevalence of forged copies so authentication is important, especially for high end vintage cards.

Modern Eras (1980s-present) – Cards from the junk wax era of the 1980s and 1990s are generally less valuable aside from rare parallels, serially numbered inserts, or star rookie cards in top condition. Newer stars are now appearing from this era which can add interest and value as they retired. Cards from the 2000s+ are generally inexpensive aside from stars but can gain value as players establish careers.

Autographs/Memorabilia – Signed cards and those containing game worn memorabilia pieces significantly increase a card’s worth, especially for star players past and present. These specialty insert sets were not common until the late 1980s and became more prevalent in the modern era as technology advanced. Prominent autographs on vintage issue cards can make them extremely valuable.

Supply and Demand – Like any collectible market, demand and supply influence worth. Popular stars and rare subsets coveted by enthusiasts increase demand and thus value over time. Conversely, cards overproduced during the ’80s-’90s junk wax era suffer from an oversupply. Scarcity and demand help dictate market value.

Grading – Professionally graded cards in third party holders like PSA or BGS are preferred and will hold value best. This authentication and protection adds a layer of security for buyers. Ungraded cards are worth less due to uncertainty in condition and authenticity.

Auctions – The true value of a card is what someone is willing to pay for it at public auction. Auction prices are often the best indicator of current market value, especially for rare vintage gems. The same card could sell for significantly different amounts depending on competitive bidding.

Older cards from baseball’s early history up through the 1970s have the most collector value – usually directly correlating to the prominence of the featured player, their condition, and the card’s relative scarcity. Modern star rookie cards can also become quite valuable as legacies are established. Often, a combination of the condition, rarity, year, player featured, and any special signatures or memorabilia also play important roles in dictating a card’s worth to collectors. While values fluctuate based on supply and demand forces, seasoned collectors recommend acquiring and holding valuable specimens as wise long term investments.