The TBC Newsletter
will keep you periodically up-to-date on what is happening at The Baseball Cube.
Major League Baseball tracks debuts as a player's first appearance in a Major League Baseball game. It sounds obvious but the distinction between a player's first appearance on a roster and his first appearance in a game exists. Service Time is calculated based on time on roster, the idea being that he gets paid for going to work, whether he participates in the lineup or not. Service Time is used for free agency and arbitration purposes. (Among other things). The debut is purely statistical and provides a quick jump to a player's first game from various sections of the site.
One important note is that players who are added to an active roster (pre or post September) and who don't get into a game, will appear on the site as if they were never on that particular team. Statistically speaking, it is not easy to track this information historically. Apologies to any players who are penalized because of this anomaly.