Triples occur when a player reaches third base after hitting the ball fair and without the benefit of a fielders choice or error. Triples are the least common type of hits in baseball and generally make up approximately 2% of all hits in a season. As a result, obtaining a triple just 10-15 times in a season is likely to put a player among the league leaders in the category.
More about Triples Leaders
Though the nature of offense has changed in the last few decades, including an offensive explosion in the late 1990s followed by something of a pitching explosion in the more recent years, the number of triples hit in a season has stayed relatively consistent (and infrequent). Triples leaders are often among the fastest players in the league and are often more likely to be left-handed players who pull the ball (triples are more likely to be hit to right field or right-center field than to left field).