On player pages, a tally of World Series titles won by the player is listed along with notable awards at the top of the page.
Clicking the Playoffs tab on tables like Standard Batting / Pitching will show the player's stats in each postseason, with a trophy icon next to World Series winning years.
The tally of championships won at the top of the page counts any year that the player played in the postseason for the World Series winning team, and also includes years where the player did not play in the postseason but was on the World Series roster. For example,
Charlie Silvera only made it onto the field in one World Series but was on the World Series roster for a further five championship teams, so he is credited with six World Series wins. For more information on players who were on World Series rosters but did not play, see the following blog post:
Players who miss the postseason entirely (through injury, for example) and are not on the World Series roster will not have that season tallied in their list of World Series wins.