When it comes to high school baseball rules, the fundamental rules are very similar to those of Babe Ruth and the Big Leagues. However, there are a few that vary, based on the state.
Aluminum for Everyone?
Most states/divisions allow the use of aluminum bats. However, some do not. For example, different leagues and divisions in Massachusetts mandate that wooden bats be used during league play, while aluminum is permitted in the state championship tournament. For the most part, aluminum bats are allowed in high school baseball rules, as broken wooden bats cost the schools extra money.
Innings and Outings
As is the case with Babe Ruth, most games last seven innings during the regular season, while playoff games are generally nine in division one. However, lower divisions often play just seven innings in the playoff tournament. Again, this is often left to the state and division to decide.
While it is widely assumed that a coach must list all available substitutes on a lineup card prior to the game's first pitch, it is not the case. It is merely (strongly) suggested that coaches list available substitutes to avoid conflict and deter the game from all disputes and delays.
What separates high school baseball rules from the Majors is a greater emphasis on sportsmanship. For example, a catcher "talking trash" to a batter, though widely accepted in the Bigs (see: Varitek vs. A-Rod), is not allowed in high school and usually results in an ejection or suspension. Additionally, a player may not blow on a baseball to make it roll fair/foul, another practice that often turns up on the Big League blooper reels.
Watch Your Mouth?
As is the case in Major League Baseball, a pitcher may not go to his mouth with his pitching hand while his foot is on the rubber; this immediately results in a balk (or a ball, if there are no runners on base). In high school baseball rules, however, a pitcher is allowed to go to his mouth provided he is "distinctly wipes" his hand on his uniform pants before touching the ball. In pro ball, a pitcher must be granted permission by the home plate umpire to go to his mouth at any time-a right that is usually only granted if playing conditions are especially cold.
No Block Parties
It is common practice to block home plate in Major League Baseball, a tactic often used by the likes of Jason Varitek and A.J. Pierzynski. However, this is strictly prohibited in high school baseball rules. It is considered obstruction for any player to block a player from reaching a base he is trying to reach without possession of the ball. If a player beats the throw, he beats the throw.
Do you want to learn how to give baseball signals? Learning how to communicate via signals will help you and your teammates strategize without giving your gameplan away.