Little League International and Mid Valley Little League 
Baseball and Softball Bat Requirements.

Testing and evaluating of youth baseball bats has evolved into a science.

So much so that the standard has also evolved to where USA Baseball, the national governing body for the sport of baseball in the United States,adopted a new method
for measuring bat performance in the testing of youth bats that went into effect
on January 1, 2018.
The new USA Baseball bat standard (USABat), was developed by a
USA Baseball committee of scientific experts.

Effective on January 1, 2018, Little League Baseball® complied with the new USABat standard. No bats previously approved for use in Little League play (Junior League Baseball and below) is permitted to be used in any Little League game or practice,
or other Little League function, event, or activity.

As of January 1, 2018, USABat Standard bats must be used in the
Little League Major Baseball Division and below.
Either USABat Standard bats or BBCOR bats must be used
at the Intermediate (50/70) Baseball and Junior League Baseball Divisions.
At the Senior League Baseball Division, all bats must meet the BBCOR standard.

For more information on the USABat standard and a complete list of
bats approved through the USABat Standard, visit usabat.com.
To view bats that have been decertified for use by USA Baseball, visit usabat.com/decertified-bats.

Be aware that the USABat standard affects Little League Baseball only.
There are no changes to the 1.20 Bat Performance Factor bat standard,
or related regulations for Little League Softball®.

Prior to the start of any Little League® game, it is the responsibility of the umpires to inspect the condition of the playing equipment to be used by the players participating in the ensuing game. To do so thoroughly and effectively, the home plate umpire and his partner(s) are to examine each of the bats that may be used in the game.

All baseball bats to be used in the Major Division and below, must be affixed with the USABat Standard marking, and deemed to be in accordance with Little League Rule 1.10 as outlined in the current edition of the Little League Rules, Regulations, and Policies. In Little League Baseball Intermediate 50/70, Junior, and Senior Divisions BBCOR bats are permitted. In each instance, all bats that may be used in the ensuing game must be void of any physical damage, or an altered state, that would prevent the bat from complying with the USABat Standard.

It is strongly recommended that the umpires complete this inspection process together. If a piece a bat is deemed unsafe, bring the decision to the attention of the team manager, identify the bat in question, and instruct that it be immediately removed from the dugout. If the bat can be repaired to the satisfaction of the home plate umpire prior to the start of the game, it is the judgment of the home plate umpire or crew chief to allow  it to be used in the game.

The process is the same for any bat that is intended to be used in the game

Like all application of Little League rules, decisions are made in accordance with the current rules, regulations, and policies, and in conjunction with the judgment of the umpires.

It is the responsibility of the team manager to understand this process, and why it is to be done prior to each game throughout the regular season.