In our discussion of interference, we said that the opposite of interference is Obstruction. That is, while interference penalizes base runners for impeding fielders who are making a defensive play, obstruction penalizes fielders who impede base runners.

Here's the rule-book definition, found in Definitions (obstruction):

Obstruction is the act of a fielder who, while not in possession of the ball and not in the act of fielding the ball, impedes the progress of any runner. 

Note the emphasis on the words "while not in possession of the ball and not in the act of fielding the ball." This is very important and is something we'll come back to. Another important point is that there does not need to be physical contact to have obstruction.

Beyond the rule-book definition, Rules 6.01(h)(1) and 6.01(h)(2) extend the definition and explain the two types of obstruction, commonly called Type 1 obstruction and Type 2 obstruction (for their treatment in Rules 6.01(h)(1) and 6.01(h)(2), respectively).

Note: The 2014 revision to the Official Baseball Rules, in renumbering the rules, has disposed of the time-honored Type A and Type B obstruction. In the new rule book, these are now. Type 1 and Type 2, respectively.

Type 1 (type A) Obstruction: Happens when a base runner is impeded while a play is being made on him. For example, if a catcher without possession of the ball blocks the plate, preventing a runner from having unimpeded access to the plate, this is obstruction. This is an immediate dead ball and bases are awarded as appropriate.

Type 2 (type B) Obstruction: Happens when a base runner is impeded when there is not a play being made on the runner. For example, when F3 is standing on first base watching a base hit to the gap and the batter-runner collides with him while rounding first, that obstruction. However, because the ball is in the outfield and no play is being made on the runner, this is a delayed dead ball. You make a signal but you let play continue and then deal with penalties (if any) after play has concluded.

Important: High school rules (NFHS Baseball Rules Book) treat obstruction differently from OBR. In NFHS, obstruction is always a delayed dead ball (never immediate dead ball). On conclusion of action, kill the ball and award bases to nullify obstruction, but always award a minimum of one base beyond the point of the obstruction. See NFHS Rules 2-22-1 and 8-3-2.

Now let's go deep on OBR Types 1 and 2 obstruction.


Type 1 obstruction

As we've said, Type 1 obstruction occurs when there is a play being made on the runner at the time the obstruction occurs. Call time immediately and award bases. We'll discuss base awards in a moment. Here are a couple of examples of Type 1 obstruction:

Catcher blocks the plate

A base runner has rounded third, heading for home, and the catcher is three feet up the line, blocking the base path, calling for the ball. The ball is in flight but before the catcher receives the ball the runner is forced to slow down and deviate from his normal path to avoid a collision. Just as the runner passes by (or slides by) him, the catcher receives the ball and applies the tag.

Do we have an out? Not on your life. The umpire calls "Time. That's obstruction! You (pointing to the runner), home." The runner is safe and the run scores. (But make sure the runner touches home plate. He can be put out on appeal if he fails to touch the plate.)

We're talking about the catcher setting up in a blocking position without possession of the ball. You must watch the catcher before the play arrives, while the play is still developing, and you must be aware of where the ball is. This will prepare you to see and call the obstruction if it occurs.

Important: One of the most difficult calls you'll ever make is when the catcher is in a legal position, but, as the runner arrives (at full speed), a bad throw pulls the catcher into the runner's path. Here you have a collision (literally) of two rules - obstruction and interference. The interference rule tells us that a fielder has the right to make a play on the ball, and yet the obstruction rule tells us that the runner has the a right to the base path.

We're in the territory of what's commonly called a "train wreck," and there is no simple answer on how best to judge this. The most common umpiring advice supports a no-call, if you judge that both players were acting appropriately. Any action on the part of either player (either the fielder moves unnecessarily to impede the runner, or the runner deviates purposely to disrupt the fielder), and take that as a cue to call either interference or obstruction. But you need to be mentally ready because this one happens fast, so again, watch the players while the play is developing.

Fielder blocks the bag

You have a runner on first (R1). It's a close game so the first baseman (F3) is holding the runner on; the pitcher throws over frequently for the pickoff, but R1 gets back each time. Finally, with R1 leading off even more, the pitcher throws to first and R1 dives back reaching for the bag but instead his hand hits F3's foot and is stopped just short of the bag. Tag is applied.

Do we have an out? You guessed it – no way. "Time. That's obstruction! You (pointing to the runner), second base." The fielder must allow a clear, unimpeded path to the base. Blocking a portion of the bag with a foot is obstruction. 

You can change up this scenario in a dozens of ways, move it to any base, and you get the same result. The point is, a fielder without possession of the ball cannot deny access to a base to a runner advancing or retreating.

Obstruction in a run-down

A run-down ("pickle") can be tricky because each time the fielders exchange the ball and the runner reverses direction, the runner has created a new base path. This is relevant because each time this happens, the fielder who just threw the ball is now probably in the runner's way, but is no longer in possession of the ball. That fielder, then, is in jeopardy of committing obstruction. You have to watch for this because it's easy to miss in the midst of a helter-skelter pickle, so (again) you have to be mentally prepared and watch the fielders (not just the runner) as the pickle develops.

We have more about this in our article, Basepath & Running Lane.

One wrinkle: "possession" vs. "imminent"

We've emphasized that a critical element of judging Type 1 obstruction is the fielder's having (or not having) possession of the ball. This begs the question: precisely what constitutes possession? Is it ball-in-glove? Or is it "imminent," that is, the ball is just arriving at the glove?

Once a player has possession of the ball, he can place himself between the runner and the base to which the runner is advancing (in fact, that's what he should do). But here's the problem: the professional rules (OBR) recognize a defensive player's right to occupy a blocking position when he is in the act of receiving the ball, when possession is "imminent." Many amateur leagues also recognize "imminent possession." Even Little League, until only a few years back (they changed in 2012, if I recall correctly) recognized imminent possession.

The problem with imminent is that one person's immanent is another person's obstruction. And therein lies a wedge of ambiguity that creates a potential for collisions (and serious injury) as the base runner hurries to beat the throw while the defender takes a wishfully blocking position in hopes of receiving the throw "imminently." Bang! It's a nearly impossible judgment call and a guaranteed argument (from one manager or the other, depending on how you call it).

Again, Little League has done away with imminent. So has the high school (NFSH) rule book, which now requires possession, as do a great many other youth programs. If you work leagues where this is not spelled out, then clarify at the plate meeting. For what it's worth, at my plate meetings I always specify that we're playing "possession," then wait to see if either manager disagrees or argues. If not, that's the rule.

And one last quirk

Rule 6.01(a)(10) Comment tells us that on a batted ball to the vicinity of home plate (a bunt, for example, or a dribbler on the first base line) if the the catcher and the batter-runner "have contact," there is normally no violation – no Type 1 obstruction. We're talking about incidental contact here, not something blatant. If you see either the runner or the fielder initiate an intentional act coincident with the contact, then make the call (interference or obstruction, depending on who initiated the contact).

Calling and penalizing Type 1 obstruction

Type 1 obstruction is a dead-ball infraction. This means, the moment you see it, call it: "Time! That's obstruction. You ... " and point to the runner and vocalize the base award "... you, second base" "... you, third base" or whatever the award calls for.

The penalty for Type 1 obstruction is awarding the obstructed runner one base beyond the base last legally touched. In the case of runners who are advancing, this means you award the base to which they were advancing. In the case of a runner obstructed while retreating (as in a pick-off attempt), award the runner the base beyond the one they were retreating to (and previously occupied).


Type 2 obstruction

In Type 2 obstruction, a fielder impedes the progress of a runner, but this takes place away from the action and away from the ball. That is, no play is being made on the obstructed runner. Instead, a fielder simply gets in the way of a base runner and causes the runner to fall, slow down, collide, swerve out of the way – anything that impedes the runner's progress.

Here are some examples of Type 2 obstruction. I'm sure you'll recognize most of these. But keep in mind that this is only a small sample of many situations that are Type 2 obstruction.

  • Here's the classic (you see this one all the time in youth baseball). Big hit to the outfield through the gap. Batter-runner figures on a double. But the first baseman is standing on the bag (or near it) watching the ball – just standing there gawking, right in the runner's path. The runner either slows down and scoots around the first baseman, or he collides, maybe falling down. In any event, there are one of three outcomes for the runner. He either abandons his attempt to get to second, or he tries for second and makes it safely, or he tries for second and gets thrown out.

    That's Type 2 obstruction, so you verbalize and signal the obstruction, but wait until action is complete before you call time and enforce the penalty – if at all. We'll go over this in the section on the penalty for Type 2 obstruction.

  • Here's one that you saw in game 3 of the the 2013 World Series, where Boston third baseman Will Middlebrooks fell flat on his face but whose raised legs tripped Allen Craig, who was trying to score from third base. Umpire Jim Joyce called obstruction (Type 2) and awarded Craig home. The press made this out to be a controversial call, but in fact this is textbook obstruction. Here's a video of the play. You can see Joyce (he's U3) signalling the obstruction right away (left arm outstretched with a fist); and then, once Craig scores, the plate umpire is pointing back to the call at third. (The announcer incorrectly calls it interference, a mistake that we hear from announcers all the time.)
  • Here's one that a lot of people don't know about. A fake tag (pretending that you have the ball and are making a play on the runner) – well, that's obstruction. Say you are a fielder and a runner is approaching second but you slap you glove like you've received the ball and so the runner quickly reverses direction to head back to first. That's obstruction. In another scenario, a runner is sliding into a base and the fielder (without the ball) lays down a tag, causing the runner to believe he's been put out. The runner gets up and starts trotting back to the dugout, whereupon the defense tags him out. That's obstruction. Nullify the out and return the runner to the base he would have achieved.

The penalty for Type 2 obstruction

Applying the penalty for Type 2 obstruction requires umpire judgment. In fact there is no prescribed penalty other than, once action has stopped (remember, this is a delayed dead ball infraction), the umpire shall call "Time" and shall "... impose such penalties, if any, as in his judgment will nullify the act of obstruction."

The emphasis on "if any" is important. It reinforces that in some cases (when, in your judgment, the obstruction is incidental and does not affect the progress of the runner) no penalty is necessary. On the other hand, you can, in your judgment, determine that the base award should be one base, two bases, or (theoretically) three bases. It's hard to imagine circumstances for a three-base award, but ... well, it's entirely in the hands of the umpire.

Mechanic for calling Type 2 obstruction

Unlike Type 1 obstruction, Type 2 obstruction is a delayed dead ball. This is important. When you see Type 2 obstruction, you verbalize it ("That's obstruction") and you point in the direction of the infraction, and as you do this you make a fist on your left hand, holding that arm out straight. But you let play continue.

When action on the play concludes, you act on the obstruction call by doing one of the following:

  • If the result of the play is such that, in your judgment, the obstruction caused the runner to be put out or to not reach the base that he would have reached had the obstruction not occurred, then you call "Time" announce the infraction, then place the runner where, in your judgement, he belongs. Other runners advance if forced.
  • If, on the other hand, the obstruction did not affect the play by causing the runner to be put out or to fail to reach base, then simply ignore the obstruction, say nothing, and move on. Often a base coach or player will have heard you verbalize "that's obstruction" and will ask you, then, why you're not enforcing a penalty. Call "Time" and explain (in three seconds or less) why you're not doing so.


Summary Table


  Type 1 Obstruction Type 2 Obstruction
Occurs when Play is being made on obstructed runner Play is not being made on obstructed runner
Action Immediate dead ball Delayed dead ball
Penalty At least one base beyond the last base touched Umpire judgment: place runner to nullify effect of the obstruction; this could be no award at all