Teacher guide

Learning objectives

By the end of the lesson, learners should be able to:

  • distinguish offensive interference from defensive obstruction;
  • identify the one fielder protected while attempting to field a batted ball;
  • recognise that interference can be called without deliberate contact;
  • separate an immediate obstruction ruling from a delayed obstruction ruling; and
  • explain why contact alone does not decide either call.
Core contrast

Start with who was hindered

Do not begin with whether the collision looked serious. Begin with the ball, the protected action, and which side prevented the other from completing it.

Defence hinders offence

Obstruction

A fielder who is not in possession of the ball and is not fielding a batted ball impedes a runner’s progress.

Usual result

The umpire protects the runner to the base or bases the runner would probably have reached. Whether play stops immediately depends on whether a play is being made on that runner.

Offence hinders defence

Interference

An offensive player hinders or confuses a fielder attempting to make a play. A fielder fielding a batted ball has priority over a runner.

Usual result

The offending runner is out, the ball is dead, and other runners return unless another rule provides a different placement or additional out.

The five-question check

  1. 1
    Was the ball batted or thrown?

    A fielder fielding a batted ball has special priority; a thrown ball does not give the same blanket protection.

  2. 2
    Who hindered whom?

    Offence hindering defence points toward interference. Defence hindering a runner points toward obstruction.

  3. 3
    Which fielder was entitled to field the batted ball?

    When several fielders converge, the umpire protects only the one entitled to make the play.

  4. 4
    Was the act intentional?

    Intent matters in some thrown-ball and post-deflection cases, but a runner can interfere with a batted-ball fielder unintentionally.

  5. 5
    Was a play being made on the obstructed runner?

    That decides whether obstruction stops play now or is resolved after the action ends.

Language of the lesson

Six terms learners need

Obstruction
A fielder without the ball, and not fielding a batted ball, impeding a runner.
Offensive interference
An act by the batting side that hinders, obstructs, impedes, confuses, or disrupts a fielder making a play.
Protected fielder
The one fielder the umpire determines is entitled to field a particular batted ball.
Immediate dead ball
Play stops when obstruction occurs while a play is being made on the runner, or before the batter-runner reaches first.
Delayed obstruction
Play continues when no play is being made on that runner; the umpire later nullifies the obstruction if needed.
Intent
A deliberate act. It is required for some interference calls, but not when a runner hinders the protected fielder on a batted ball.
40-minute lesson

Teaching sequence

  1. 0–5

    Expose the misconception

    Ask: “A runner and fielder collide. Who is at fault?” Record answers, then explain that the rule cannot be decided until the group knows what the ball and fielder were doing.

  2. 5–13

    Build the contrast

    Use the two cards above. Have learners point from the side doing the hindering toward the side being hindered, then name the possible call.

  3. 13–20

    Add priority and timing

    Model two fielders approaching one ground ball. Protect one. Then contrast obstruction during a rundown with obstruction while the ball is elsewhere.

  4. 20–34

    Make the calls

    Learners complete the eight situations. Require a ruling, the entitled player, and one decisive fact.

  5. 34–40

    Debrief

    Sort the situations into interference, obstruction, and neither. Ask which examples prove that contact and intent are unreliable shortcuts.

Sport Rules teaching material · Baseball

Learner sheet: who hindered whom?

For each play, name the ruling and the decisive fact. These situations use the 2026 MLB Official Baseball Rules.

Name
Date
Decision reminder
  1. Locate the ball.
  2. Identify who hindered whom.
  3. Decide which fielder, if any, had priority.
  4. Choose interference, obstruction, or neither—and explain why.
  1. 1

    The ground-ball collision

    Batted ball

    R1 runs from first toward second and collides with the shortstop while the shortstop is moving into position to field a ground ball. R1 did not mean to cause contact.

    What is the ruling?

    RulingDecisive fact
  2. 2

    Two fielders, one protected

    Batted ball

    A slow ground ball draws the shortstop and pitcher together. The umpire judges that the shortstop is entitled to field it. R1 avoids the shortstop but bumps the pitcher, who has crossed the running path.

    Is R1 automatically guilty of interference?

    RulingDecisive fact
  3. 3

    The blocked path to first

    Before first base

    The first baseman has no ball and is not fielding the batted ball. Standing in the batter-runner’s path, the fielder makes the batter-runner slow and detour before reaching first.

    What should the umpire call, and when does play stop?

    RulingDecisive fact
  4. 4

    Bumped while rounding second

    No play on runner

    R1 is rounding second on a hit to the outfield. The shortstop, who has no ball and is not fielding the batted ball, bumps R1 off stride. No throw is being made toward R1.

    Does play stop immediately, and how is the runner protected?

    RulingDecisive fact
  5. 5

    A rundown roadblock

    Play on runner

    R2 is trapped between second and third. While a throw is coming toward third, the third baseman—still without the ball—blocks R2’s path and causes R2 to stop.

    What is the call and base award?

    RulingDecisive fact
  6. 6

    Hit by a throw

    Thrown ball

    R1 runs normally toward second. A fielder’s throw accidentally strikes R1 in the back. R1 did not look back, wave an arm, or alter course to meet the ball.

    Is this automatically interference?

    RulingDecisive fact
  7. 7

    The deliberate swat

    Thrown ball

    Seeing a throw headed toward second, R1 deliberately knocks it away with a hand to prevent the defence from completing a play.

    What is the ruling?

    RulingDecisive fact
  8. 8

    Past the first infielder

    Deflected ball

    A fair ground ball glances off the third baseman, then strikes R2 running behind the fielder. No other infielder has a chance to make an out. R2 did not deliberately touch the ball.

    Is R2 out for being hit?

    RulingDecisive fact
Teacher copy

Answer key and reasoning

Credit the ruling only when the explanation identifies the protected action and the player who hindered it.

  1. Interference; R1 is out and the ball is dead.

    A runner must avoid a fielder attempting to field a batted ball. Intent is not required in this situation. Other runners return unless another rule sets a different placement. Rules: 5.09(b)(3) and 6.01(a)(10).

  2. No interference; consider obstruction.

    Only one fielder is entitled to protection on a batted ball, and the umpire selected the shortstop. Contact with the other fielder does not make R1 out. If the pitcher’s position impeded R1, the pitcher is instead subject to an obstruction call; an intentional act by R1 could still change the ruling. Rules: 6.01(a)(10) Comment and 6.01(h).

  3. Obstruction; the ball is dead immediately.

    The fielder without the ball impeded the batter-runner before first base. The batter-runner is awarded at least first, with other runners placed to nullify the obstruction. Rule: 6.01(h)(1).

  4. Delayed obstruction; keep play live for now.

    No play was being made on R1. The umpire signals obstruction, lets the action finish, then awards the base or bases R1 would probably have reached without the bump. Rule: 6.01(h)(2).

  5. Obstruction; immediate dead ball and an award to third.

    A play was being made on the obstructed runner. R2 receives at least one base beyond the last base legally touched before the obstruction, so R2 is awarded third. Rule: 6.01(h)(1).

  6. No interference solely because the throw hit R1.

    A runner is not automatically out when a thrown ball accidentally strikes them during normal running. Deliberately interfering with a thrown ball would change the ruling. The ball remains live absent another violation. Rule: 6.01(a)(10).

  7. Interference; R1 is out and the ball is dead.

    R1 intentionally interfered with a thrown ball. Other runners return to the last bases legally touched at the time of interference unless another provision applies. Rules: 5.09(b)(3) and 6.01(a)(10).

  8. R2 is not out solely for being hit.

    The fair ball had passed or deflected from an infielder and no other infielder had a play. The ball remains live. A deliberate kick or touch by R2 would instead be interference. Rules: 5.09(b)(7) and 6.01(a)(11).

Discussion prompts

Push the reasoning one step further

  • Why is “who made contact?” a weaker question than “who had priority?”
  • What makes situation 4 a delayed call but situation 5 an immediate dead ball?
  • How would situation 2 change if R1 deliberately shoved the pitcher?
  • Why should an umpire signal delayed obstruction even if the runner later reaches the expected base?
Official references

Rule basis and further reading

This material paraphrases the rules for teaching; it does not replace the official wording.

  • 2026 MLB Official Baseball RulesRules 5.09(b)(3) and (7), 6.01(a)(10)–(11), 6.01(h), and the definitions of Interference and Obstruction.
  • MLB: ObstructionAn official overview of immediate and delayed obstruction calls.
  • MLB: InterferenceAn official introduction to offensive, defensive, umpire, and spectator interference.