Cricket
A somewhat vague and not nescessarily accurate beginners guide to Cricket, somewhat more or less aimed at Americans. So, G'day :)
Cricket is a sport played primarily by Commonwealth (as in, 'once was the English Empire') nations.
Why is Cricket so confusing to Americans?
In most sports which are not cricket, the 'winning condition' is a simple points value (in football it's simple, in tennis a little less so, but still basically simple) - and the points are scored by the player who is 'attacking'. In fact, the purpose of the attack is to score points. Players/teams on the defence tend not to score points.
In cricket however... it's all backwards. At a player level, the bowler is the attacker, whilst the batter is the defender. The batsman's primary purpose is to defend his wicket. The bowler attacks the wicket to dismiss the bowler (get him out).
So in cricket, runs (points required for winning) are scored by the defender when he defends particularly well! The bowler intent in dismissing the batsman (an attacking gesture at a player-level) is to limit the opposing teams runscoring ability (a defensive gesture at a team-level)
In fact, at a team level either side can be defending or attacking in either position of batting side, or bowling side - according to the larger state of play, the tactics involved, etc. (Bowlers can bowl to 'defend against runs being scored' rather than trying to attack the wicket, batsmen may play to score runs as a prime objective rather than to defend their wicket - a more interesting spectator sport.
Indeed, the development of 'short forms' of cricket (one-day, and 20-20) can be attributed to finding ways in which the team tactics are biased as much as possible towards the 'batsmen must score runs' strategy (ie, considered to be much more spectator/TV friendly)