15/10 Mercy Rule Explained

In mid-2018, Little League International introduced a new variation of the mercy rule. The new 15/10 Mercy Rule was optional for the Spring 2018 regular season but goes into effect for the 2018 All-Star season and beyond. This article covers the rule and how it applies in game.

The Rule

Rule 4.10(e): If after three (3) innings [Intermediate (50-70) Division/Junior/Senior League: four innings], two and one-half innings [Intermediate (50-70) Division/Junior/Senior League: three and one-half innings] if the home team is ahead, one team has a lead of fifteen (15) runs or more, the manager of the team with the least runs shall concede the victory to the opponent. If after four (4) innings [Intermediate (50/70) Division/Junior/Senior League: five innings], three and one-half innings [Intermediate (50/70) Division/Junior/Senior League: four and one-half innings] if the home team is ahead, one team has a lead of ten (10) runs or more, the manager of the team with the least runs shall concede the victory to the opponent.

NOTE: (1) If the visiting team has a lead of fifteen (15) or ten (10) runs or more respectively, the home team must bat in its half of the inning.

NOTE: (2) The local league may adopt the option of not utilizing this rule.

KNLL Application of the Rule

KNLL Softball participates in an Inter-league Program organized by District 9 (D9) due to the limited number of Softball teams that can be formed within our league. D9 acts as the governing body for the Inter-league Program and all Leagues participating will follow the rules established for Inter-League play. At times the Inter-league rules may vary from the rules put forth by KNLL in its Local Rules or for Baseball.

Example Scenarios

The following chart covers the typical scenarios to help managers and coaches navigate the rule. The examples are written for Majors Division and below. For Juniors, since they play a 7-inning game instead of 6-innings, the 15-run rule first comes into play at inning 3.5 and the 10-run rule comes into play at inning 4.5. Note that during the bottom half of an inning, if the home team reaches the relevant run differential, the game is called immediately by the umpire right after the qualifying run is scored and no additional runs are scored.

Rule 4.10(e) - 15/10 Scenarios
Inning(s)	Scenario	Result
After 2.5 innings (the visiting team has batted 3 times but before the home team has come up to bat) Juniors- 3.5 innings	The home team has a lead of 15 runs	The umpire will call the game per rule 4.10
After 3 innings (both teams have batted 3 times) Juniors- 4 innings	One of the teams has a lead of 15 runs	The umpire will call the game per rule 4.10
After 3.5 or 4.5 innings Juniors- 4.5 or 5.5	The home team has a lead of 10 runs	The umpire will call the game per rule 4.10
After 4 or 5 innings Juniors- 5 or 6	One of the teams has a lead of 10 runs	The umpire will call the game per rule 4.10