Obstruction
Obstruction is defined in rule 2-22 as an act (intentional or unintentional, as well as physical or verbal) by a fielder, any member of the defensive team, or its personnel that hinders a runner or changes the pattern of a play as in 5-1-3 or 8-3-2. This article is going to focus on plays at the plate, but the reasoning applies at all bases.
There are two situations I was asked to present that I want to address regarding obstruction. First, we know that if the runner is rounding third base and the catcher blocks the plate without possession of the ball, 90 feet away, it is not obstruction. The question posed to me in this situation is how close does the runner have to get to the catcher who is blocking the path without the ball before its obstruction. Assuming the catcher stays at the plate and does not move up the line (we will get to that next), the answer generally is, close enough to be obstructed. NFHS case play 2.22.1, situation B sort of covers this. If the runner changes direction or slows down or is otherwise hindered by the catcher being in the base path without possession of the ball, its obstruction. Generally, usually, normally, most of the time, this occurs once the runner reaches the dirt circle.
The second question is what happens when the throw brings the catcher (or another fielder) into the path of the runner before the catcher has possession of the ball. College and pro baseball have an exception to the obstruction rule that if the fielder was originally set up in a non-obstructing position and the throw causes the fielder to move into the runners path and hinder the runner, there is no obstruction. NHFS does not have such an exception (see case play 2.22.1 situation C and case play 8.3.2 situation C). Under NHFS, the fielder either has possession of the ball or does not. If the fielder hinders the runner without possession of the ball, whether the throw pulled them into the runner’s path or not, it is, by letter of the law, obstruction.
The penalty for obstruction in high school baseball is a minimum of one base beyond the last legally acquired base, whether or not the runner is advancing or returning to the base. Rule 8-3-2). In the case of a runner attempting to score, the runner would simply be awarded home.
Bob Nasser
MAC/NVBUA Rules Interpreter