Substitutions

Each team is allowed to substitute for any player at any time the ball is dead. A batter who replaces another batter is referred to as a pinch hitter; similarly, a pinch runner may be used as a replacement for a baserunner. Any player who replaces another player between innings is known as a "defensive replacement". Any replacement is a permanent substitution; the replaced player may not return to the game.~

Statistics

As with many sports, and perhaps even more so, statistics are very important to baseball. Statistics have been kept for the Major Leagues since their creation, and presumably statistics were around even before that. General managers, baseball scouts, managers, and players alike study player statistics to help them choose various strategies to best help their team.

Popularity

Baseball is most popular in East Asia and the Americas, although in South America its popularity is mainly limited to the northern portion of the continent.
Baseball is played at a number of levels, by amateur and professionals, and by the young and the old.