The numbers found on baseball cards serve different statistical and identification purposes. Let’s take a closer look at some of the most common numbers seen on cards and what they represent:

uniform number – This is the number the player wears on their jersey when playing in games. Uniform numbers have no set meaning but are simply used to identify individual players on the field. Numbers were first introduced in the 1920s and some single digit numbers like #3, #5 and #7 became very popular choices over the years. Certain numbers like #42 have been retired league-wide in honor of players like Jackie Robinson. Other notable uniform numbers include #20 worn by players like Willie Mays and #7 worn by Mickey Mantle.

season and year – This indicates the specific season and year the card is from. For example, a card may say “1987 Topps” to denote it features stats and images from the 1987 MLB season. Pinpointing the year helps provide important context for the player’s career stage and team situation depicted on the card.

player name – Clearly stating the player’s full name leaves no question as to who the card features. Before players began regularly putting their names on the backs of their jerseys, cards helped cement the proper spelling and order of players’ names.

team name – The team logo and sometimes full team name is displayed to acknowledge which Major League Baseball franchise the player was representing during the season featured on the card. This could be important for tracking player movement between teams over their careers.

batting average – This statistic, represented as a decimal number between .000 and 1.000, shows the player’s batting average for the season. It measures how many of their plate appearances resulted in a hit. Batting average is one of the most classic and fundamental individual offensive stats tracked in baseball.

home runs – The total number of home runs the player hit crossing all games played during the season in question. Home runs demonstrate a player’s power and ability to drive the ball over the fence for an automatic base hit. Home run totals remain one of the most followed stats for assessing sluggers.

runs batted in (RBI) – An RBI denotes when a player’s actions directly resulted in a run being scored by a teammate. It shows their ability to drive runners home and produce runs offensively. Like home runs, RBI reflects a player’s “clutchness” and ability to deliver in run-scoring situations.

games played – The total number of regular season games the player participated in, whether as a starter or a bench player, helps provide context on their availability and role on the team that year. Playing time and durability factor into their statistics and worth to the club.

position – Listed as a one or two-letter abbreviation, this indicates the primary fielding position or positions the player played during the season in question, such as P for pitcher, C for catcher, 1B for first base, etc. Knowing a player’s position helps collectors understand their full on-field contributions.

age – The player’s age as of June 30th of the season depicted on the card. Age factors heavily into player projections and contract status, as most players hit their statistical peaks during their late 20s. Younger players held more potential and upside, while older players were closer to retirement.

In addition to these numerical stats, modern cards may also list statistics like wins for pitchers, saves for relievers, stolen bases, slugging percentage, on-base percentage, ERA or WHIP that provide a fuller picture of a player’s skills and contributions.Serial numbers or production codes can also serve to verify a card’s authenticity and rarity level for collectors. The assortment of numbers found on baseball cards offer a wealth of useful biographical and statistical context to identify and evaluate players throughout their MLB careers.