[Skahtboi]

Here, for example, is the LBR from the NCAA rulebook:

Look-Back Rule
SECTION 21. a. The look-back rule is in effect when the ball is live, the
batter-runner has touched first base, there are one or more runners, and
the pitcher has possession (that is, holds the ball in her hand or gloved
hand) and control of the ball within the pitcher’s circle. The pitcher is
considered to be in the pitcher’s circle when both her feet are within the
circle or on the lines.
b. When a runner is legally off her base after a pitch or as a result of a
batter completing her turn at bat, and she is in motion as the pitcher
takes possession of the ball within the pitcher’s circle, the runner may
continue moving forward in the direction she is going without stopping;
or she may immediately and directly go back in the other direction. If the
runner is stopped as the pitcher takes possession of the ball within the
pitcher’s circle, the runner must immediately and directly go forward or
back. A base on balls or a dropped third strike is treated as a base hit as
long as the batter-runner continues past first base.
c. Once the runner has determined a direction, she may not reverse
direction unless the pitcher:
1. Throws the ball from within the pitcher’s circle.
2. Carries the ball outside the pitcher’s circle.
3. Has one foot completely outside the pitcher’s circle, on the ground,
and is in possession of the ball.
4. Sets the ball on the ground or no longer has the ball in her hand or
gloved hand.
5. Loses possession of the ball, including handing it to another player.
6. Makes a play on the runner or another runner.
Note: When the pitcher’s circle is not visible, the umpire must use good
judgment.
d. The pitcher is considered to have made a play if:
1. She fakes a throw.
Note: Raising the throwing arm into throwing position is considered a fake
throw regardless of whether the pitcher’s arm moves forward.
2. She makes any aggressive body movement toward the base runner
(e.g., steps toward the runner, head and body fakes toward the
runner).
e. There is no obligation on the part of the pitcher to look, fake or throw
in order to force the runner to comply with the look-back rule. The
obligation to comply rests solely with the runner.
f. When the pitcher takes possession of the ball within the pitcher’s
circle:
1. A runner standing off her base must immediately return to the base
she last occupied or advance to the next base.
2. A runner who starts back to the base she last occupied or starts
forward toward the next base shall not stop or reverse direction.
3. The batter-runner may not step off any base after stopping at it.
188 RULE 12 / BASE RUNNING
4. The batter-runner, after overrunning first base, may not retouch the
base and advance toward second base.
5. The batter-runner, after overrunning first base, must immediately
return nonstop to first base or, if she does not retouch first base, must
make an attempt to advance to second. If after passing the base, the
runner is heading back toward first within the basepath extended, she
may make a decision to go to either base. However, stepping beyond
the extended basepath in foul territory commits the runner to first
base while stepping beyond the basepath toward the second- base
side commits the runner to second base.
EFFECT (1-5)—The ball is dead, the offending runner is out, and each
other runner must return to the last base legally touched at
the time of the infraction. If two runners are off base and
both runners are called out, the umpires must determine
which runner was called out first as it is not possible to obtain
more than one out under the look-back rule. The ball is dead
when the first runner is called out, and the other runner must
return to the base last touched at the time of the infraction.