An official game in baseball - also sometimes called a regulation game - is a game that has progressed beyond the point at which it could be considered complete, if subsequent events occurring in the prosecution of the game make such a determination necessary. This is approximately the halfway point of the game. In Major League Baseball playoff games are not complete until the trailing team has batted nine innings. This rule also applies for tiebreaker games for playoff positions.
Inclement weather
In the case of inclement weather, any game which has reached this point may be stopped and shortened as needed, with the result being final, and all records and statistics counted. A game which has not reached this point before being stopped is either considered a suspended game, or is simply canceled and replayed from the start. In either case, no statistics are counted until the game becomes official. Since most professional baseball games are nine innings long, the fifth inning is used as the threshold for an official game. If the visiting team is leading, or the game is tied, the end of the fifth inning marks this point. If the home team is already ahead in the score, and theoretically would not need its half of the fifth inning, then 4½ innings is considered an official game. The game is also considered official if the home team scores to take the lead in the bottom of the fifth inning, since the game would end immediately if the same thing happened in the ninth. Games that are stopped due to power outages are treated as suspended and cannot be declared official. In the Major League Baseball postseason and all tiebreaker games that are added to the end of the regular season, this rule does not apply; all games stopped at any time for weather or power outages are considered suspended and continued from the point of stoppage when play resumes, no matter if the game has reached the end of the fifth inning. This rule was put into place as a result of Game 5 of the 2008 World Series, which was the first postseason game in history to be suspended and resumed from the point of suspension. Prior to the 2009 postseason, a playoff game had to have at least five innings completed in order to be suspendable; a playoff game stopped prior to that point had to be started over.
Rain check
In nearly all cases, the "official game" status is used to determine whether a rain check will be honored for fans holding tickets. If a game is started but does not reach the point of becoming official, fans are entitled to a new ticket for the make-up game or any other available game of their choice. If a game is halted after it becomes official, the game is simply shortened and no rain check is given.
Effects on statistical streaks
The "official game" statistic received some attention during the 1995 season, when Cal Ripken, Jr. was approaching the record for consecutive games played, previously held by Lou Gehrig. Large numbers were hung on the side of the B&O Warehouse at Oriole Park at Camden Yards to show the number of games in Ripken's streak. Each day, a new number was unfurled during the fifth inning after each game had become official. A similar practice has been used to count down toward the demolition of several stadiums ; as each game became official, the team would unveil a new number showing the number of games left to be played in the stadium.
Other sports
Other professional sports utilize similar rules regarding "official" games/events. Most codes of motorsport declare a race "official" with an official result if just three laps are completed, though only half the normal championship points are awarded if less than 75% of the race distance is completed. If more than 75% of the race is completed, full points are awarded. The major exception applies in the United States, mainly in NASCAR and INDYCAR, where races must go at the next full lap after halfway. A race is considered "official" if it has completed half the scheduled distance plus one additional lap. For instance, the Indianapolis 500 must complete 101 laps to be considered official.
