Inside the Park Home Runs

Arizona Diamondbacks - Ryan Roberts
Wikipedia - "In baseball parlance, an inside-the-park home run, 'leg home run', or 'quadruple', is a play where a batter hits a home run without hitting the ball out of play. To score an inside-the-park home run, the player must touch all four bases (in the order of first, second and third, ending at home plate) before a fielder on the opposing team tags him out. If the defensive team commits an error during the play, it is not scored as a home run, but rather advancing on an error. In the early days of baseball, with outfields more spacious and less uniform from ballpark to ballpark, inside-the-park home runs were common. However, in the modern era, with outfields less spacious, the feat has become increasingly rare, happening only a handful of times each season."
Wikipedia
Baseball Almanac
SABR: Inside the Park Home Runs