Section 6: Scoring
6.1 How Runs Are Scored (OBR Rule 5.08)
Per OBR Rule 5.08(a), one run shall be scored each time a runner legally advances to and touches home base before three men are put out to end the inning. Exception: A run is not scored if the runner advances to home during a play in which the third out is made by the batter-runner before reaching first base, or by any runner being forced out, or by a preceding runner who is declared out on appeal.
6.2 The Home Run
A home run occurs when a batter hits a fair ball over the outfield fence in flight. Per OBR Definitions (Home Run), the batter is awarded home base and all runners on base also score. A fair ball that bounces over or through the outfield fence is ruled a ground-rule double, not a home run. An "inside-the-park home run" occurs when the batter and all preceding runners reach home on a batted ball that remains in play throughout.
6.3 Earned and Unearned Runs (OBR Rule 9.16)
Per OBR Rule 9.16, an earned run is any run for which the pitcher is held accountable — i.e., a run that scores without the benefit of an error or passed ball. An unearned run is charged to the pitcher only if it would not have scored but for a fielding error or passed ball. The official scorer is responsible for determining which runs are earned and which are unearned.
6.4 Extra Innings and Tiebreakers
If the score is tied at the end of nine innings, additional innings are played until a winner is determined. Per OBR Rule 7.01, starting in the 2020 season (COVID-shortened season) and adopted permanently for the 2023 season onward, MLB uses the "Manfred Rule" (runner on second base to start each extra inning): each half-inning of extra innings begins with the player who made the last out of the preceding inning placed on second base. This rule is confirmed in MLB's current collective bargaining agreement and rule amendments for the 2022 CBA period.
6.5 Official Scorer (OBR Rule 9.01–9.02)
Per OBR Rule 9.01, the Official Scorer shall observe the game from a position in the press box and shall have sole authority to make all decisions involving judgment, such as whether a batter's advance to first base is the result of a hit or an error. All decisions by the Official Scorer are final unless reversed by the Commissioner. The Official Scorer shall report all scoring decisions to the official statisticians of the league.
6.6 Regulation Games (OBR Rule 7.01–7.04)
Per OBR Rule 7.01, a regulation game consists of nine innings, unless extended because of a tie score, or shortened because the home team needs none of its half of the ninth inning or only a fraction of it, or because of weather or other causes. A game is considered "official" (a regulation game) after five innings (or 4½ innings if the home team is ahead), per OBR Rule 7.01(a). If a game is called before becoming a regulation game, it is a "no game" and must be replayed from the beginning.
Per OBR Rule 7.02, if a game is called after it has become a regulation game and the score is tied, it is a suspended game and must be resumed from the point of suspension. If a game is called after it has become a regulation game and one team is ahead, the game is complete and the score at the time of the call is the final score.