Straightforward Offside

Jim, a U13 – U19 coach, asks:

A player is on a breakaway and scores with a clean shot past the goalie. The goalie makes an aggressive tackle and injures the player on the play inside the 18 yard line. The goal is subsequently called off because of an offside violation.  Obviously the goal is not allowed, but what is the correct call in relation to the dangerous tackle on the now injured player?

Answer

We are going to treat this as  a straightforward sequence of play and not delve into any of the possible complications, interesting though some of them might be.  Accordingly, our answer is based on the following: attacker makes a shot on goal which goes into the net, then the defending goalkeeper aggressively tackles the opponent and injures him, then the decision is announced that the goal is not allowed based on the attacker having committed an offside violation.

 

Where several offenses occur sequentially (i.e., one after another), the first offense determines the restart.  Here, the first offense was an offside violation so the punishment is an indirect free kick taken from where the attacker became involved in active play by touching the ball (which subsequently went into the net so the apparent goal has to be canceled).

The second offense was a tackle which, by its description, would seem to meet the definition of having been taken with excessive force and without regard for the safety of the opponent. However, because play was already considered to have been stopped when the offside offense was committed, the goalkeeper’s action was not a foul but it is misconduct.  The goalkeeper should be sent off and shown the red card for violent conduct.

Just as an indication of how and where this could become sticky, the offside offense and the excessive force tackle could have happened at the same time — we would not like to try to figure that one out.  Most referees would probably avoid the problem by declaring the events were sequential rather than simultaneous.

Offside — U-10 Version

Esther, a U-12 and under fan, asks:

I was watching a U10 game.  R9, a Red forward, had been hanging out offsides. The ball got kicked up the field towards the goal Red was attacking and it passed R9. He ran after it and kicked it. The ref called him offsides. My question is this: was he offsides because he was offsides before the ball passed him or was he onsides because he didn’t touch the ball until after it passed him? Note: the other team’s defenders weren’t involved–they weren’t even on their side of the field!

Answer (see also “Apology” posted on July 5)

We are sighing (metaphorically) as we face once again a question regarding Law 11 (Offside) which we can’t really answer because crucial information is missing.  Why is this so?  It’s not because someone is deliberately withholding it but, rather, because (we’re guessing here but guessing based on a lot of experience) so many people don’t know what “offsides” is and therefore don’t know what the Referee has to know in order to make the correct call.

Pardon us if we vent just a little bit more.  There is no such thing as “offside” — indeed, there is no way using proper English that the word “offsides” would ever be correct.  Moreover, in the offered scenario above, the word (plus it’s kissing cousin, “onsides”)  was used five times and in each case it is arguable as to which of the two standard meanings was intended.  So, let’s start:

  • Offside Principle #1: There is no such thing as “offside” unless the word is paired with one of two other words — position or violation.
  • Offside Principle #2: An “offside position” is a condition an attacker acquires by being in a certain place at a certain time.
  • Offside Principle #3: An “offside offense” is a violation of the Law and, in most cases, is punished by stopping play and giving the opposing team an indirect free kick.
  • Offside Principle #4: Every offside offense requires being in an offside position but being in an offside position is not by itself an offense.  In logic, this is can be stated as “An offside position is a necessary but not sufficient condition for an offside offense.”

One more thing before we move on to the substance of the question.  Most U-10 recreational soccer teams (boys or girls) use what are called “small-sided” soccer rules rather than the “full blown” Laws of the Game and these “small sided” rules were set up years ago by the US Youth Soccer organization affiliated with US Soccer.  Those rules do not include Law 11.  In brief, therefore, we were confused right at the very start when the scenario implicitly declared they were two U-10 teams which were apparently using “offside” in their game.  Certainly, this is possible because many local organizations have their own special local rules that don’t always follow what the national or state soccer organizations say they should.  Given this is is apparently the case here, it becomes impossible to guess what those rules may be since, technically, they shouldn’t be there at all.

Accordingly, the only thing we can do is to discuss the scenario as though the teams involved were using Law 11 exactly, without any special local rules.

R9 had every right to be where he was (although it must be noted that Law 11 was intended to be a specific deterrent to “hanging out offsides”) — which we are going to translate as “offside position” because that is the only meaning it could have at this point.  This makes the further assumption that the designation of “offside position” was used in the meaning of Law 11 that R9 was past the midfield line, passed the ball, and past the second-to-last defender while one or more of his teammates had possession of the ball.  We assume that, when the ball was kicked “up the field,” it was kicked by a teammate of R9.  When R9 “ran after it and kicked it,” he committed an offside offense (becoming involved in active play by interfering with play — kicking the ball — while in an offside position.  He was, therefore, correctly and appropriately called for this offside offense.

R9’s offside position was created the moment his teammate kicked the ball while he occupied the position we described above.  He kept the offside position through anything and everything that happened between the time his teammate kicked the ball until he committed the offside offense … which is when play was stopped by the referee’s correct decision. No other issues were involved.  A9 could have not run after the ball and, though still in an offside position, would not have committed an offside offense.  A9 could even have started running after the ball and still not have committed an offside offense so long as he did not touch the ball or interfere with an opponent.

Choosing the Offside Violation

Brenden, an adult amateur player, asks:

A5 makes a run with the ball towards goal while his teammate A12 is also moving downfield ahead of A5.  During this phase of play up to the moment when A5 last touches/plays the ball, A12 is onside but mistimes the continuation of his run such that, when his teammate last plays the ball, A12 is in an offside position while another attacker, A18, is onside.  A12’s run draws the attention of D34 who begins to move toward A12 to cover him.  However, A5’s last play of the ball is a pass to A18 who is unmarked as a result of D34’s diversion toward A12.  Can the referee rule an infringement against the attacking side on the basis that they gained an advantage from A12’s offside position?

Answer (see also “Apology” posted on July 5)

The easy answer here is, No, because “gaining an advantage” is not technically a basis for an offside violation.  It is used only under special circumstances which involves a ball which has either”rebounded or been deflected off the goalpost, crossbar or an opponent” or “been deliberately saved by an opponent” (see Law 11.2, 2016/2017 Laws of the Game).  The sole purpose of this section of Law 11 is to make clear the offside position of an attacker is not changed by (1) any contact between the ball and things considered “part of the field” (inanimate such as a goalpost or animate such as the referee) or (2) the ball  rebounding/deflecting from an opponent or (3) contact by the ball with an opponent which is deemed to be a “deliberate save”).  Since there was no such intervening contact by the ball with anything inanimate or with a defender (either accidental or deliberate), the “gaining an advantage” element in Law 11 is completely irrelevant.

That leaves just three possibilities for the only attacker carrying an offside position: (1) A12 committed no offside violation at all, (2) A12 committed an offside violation by interfering with play, or (3) A12 committed an offside violation by interfering with an opponent.  Note that, once A18 makes contact with the ball from A5’s pass, all offside position decisions have to be re-evaluated, following which A5 might not be in an offside position at all.

Prior to A18’s contact with the ball, did A12 interfere with play?  No, because A12 made no contact with the ball.  Indeed, while we do not know where A12 was relative to A18, we presume they were far enough away from each other that a ball passed to A18 could not reasonably be considered even within the vicinity of A18.  No contact, no offside violation based on “interfering with play.”

Prior to A18’s contact with the ball, did A12 interfere with an opponent while in an offside position?  There are four alternative actions which could be considered “interfering with an opponent” but only the fourth one is potentially relevant: “making an obvious action which clearly impacts on the ability of an opponent to play the ball.”  Remember, an action of this sort is entirely legal if performed while in an onside position.  So, did D34 begin his run before or after A2 was in an offside position … which translates into whether D34 began his move toward A12 before or after A5 passed the ball to A18?

We think there would be no reasonable dispute that A12 did not commit an offside violation if D34 began running to cover A12 before A5 passed the ball because an offside violation cannot be committed if the player in question was not even in an offside position  at the time.  Nor could there be any reasonable dispute that A12 did not commit an offside violation at the moment he came into an offside position if, at that moment, he stopped running, even if D34 continued in his effort to reach A12 to “cover him.”

If A12 continues or initiates a run downfield after A5 passes the ball to A18, we are now into a grey area of angles and distances.  The offside violation dispute would virtually disappear if A12 turned and began running back towards his end of the field or began running toward the touchline to his right (away from the direction of play), even if D34 followed him.  It would be difficult to argue under these circumstances that D34’s “ability … to play the ball” was being impacted since he was running away from the ball (indeed, to make matters more apparent, he would be pursuing an attacker, A12, who didn’t need “covering” while running away from A18 who did need covering!).  In many referee circles, if A12 began running as described, this would be interpreted as a clear body language statement that A12 did not wish to be involved in active play.

Where light grey starts becoming dark grey is if, at the moment A12 acquired an offside position, he continued or initiated his run downfield but not toward where the ball was being passed from A5 to A18 and this behavior arguably “drew” D34 away from moving to cover A18 by enticing him to begin running toward A12.  We believe this situation was of D34’s own making.  It was not an action by A12 which impacted on D34’s ability to play the ball — that was created by D34 running away from the ball (indeed, away from the entire area of active play) to pursue the chimera of A12 possibly receiving the ball and having a referee unable to decide correctly that, if that happened, it would be an offside violation.

To finish off what is already a lengthy but we hope stimulating discussion, there are the changes to Law 11 made this year (in the 2017/2018 edition of the Laws of the Game) which we believe both clarified and solidified the conclusion we have reached that A12 has not committed an offside violation.  The International Board added a proviso that, if an attacker in an offside position were fouled “before playing or attempting to play the ball, or challenging an opponent for the ball,” the foul itself would be penalized “as it has occurred before the offside offense” {we’ve Americanized the Board’s spelling).  This seems to us to be a very compelling reason to argue that an offside offense has not yet occurred while running to the ball or the ball is running to the attacker or the attacker is not challenging for the ball,

 

Offside Once More

Darrell, an adult amateur player, asks:

Can you comment on examples of circumstances which allow for the offside sanction even though the player in the offside position has not yet touched the ball?

Answer (see also “Apology” posted on July 5)

Sure.  In fact, we have been known to comment on just about anything involving soccer (for exceptions, see the “About” page).  So, let’s review for a moment.  Law 11 says that, once a player is in an offside position, there are certain things that player cannot legally do: (1) interfere with play, (2) interfere with an opponent, and (3) gain an advantage by being in the position.

For purposes of this answer, we can ignore (3) because, actually, it is not an independent or separate way of committing an offside offense.  It has more to do with issues related to the offside position.  Even the terms of “gain an advantage” in Law 11 themselves rely on a player in an offside position committing an offense only if he or she interferes with play or interferes with an opponent.

We come back now to the specific question that asks whether a player in an offside position can be charged with an offside offense without having “touched the ball” and the answer has to be, yes, because there is a whole second category of offside offenses that don’t involve touching the ball at all.   An attacker can also be punished for an offside offense if he or she, while in an offside position, blocks an opponent’s line of vision, challenges an opponent for the ball, or makes an obvious action which clearly impacts on the ability of an opponent to play the ball.

There you have it — three specific ways to commit an offside violation without ever having to touch the ball.

Dropped Balls and Offside

Alan, an adult amateur referee, asks:

With the LOTG 2016-2017 changes, can a person who receives the ball directly from a dropped ball be considered in an offside position?

Answer (see also “Apology” posted on July 5)

Nope, but the question you are asking has nothing to do with any of the Law changes that occurred in 2016-2017 (or, as a matter of fact, in 2017-2018 either).  The possibility of being in an offside position was decided decades ago when the offside position was defined as requiring four things.  the player in focus must (1) at the moment the ball is touched/played by a teammate, (2)  be ahead of the ball, (3) ahead of the second-to-last defender, and (4) ahead of the midfield line.  The simple truth is that the dropped ball lacks (and will always lack) requirement (1).  Because the ball is put into play by the Referee, whichever player makes initial contact with the ball once it is in play will not have been preceded by a touch/play of the ball by a teammate.  Ergo, no offside position — ever.

Now, once that player makes contact with the ball (assuming the ball made contact with the ground first), any teammate of that player is subject to being in an offside position based on requirements (2) – (4).

Perhaps what you were thinking of when you posted your question was the issue of whether a goal could legally be scored “directly” by the player who first makes legal contact with the ball at a dropped ball restart.  Unfortunately, that is a different question and, if that is what interests you, please submit it for consideration (the answer, by the way, is no).

Offside Issue

Jose, an adult amateur fan, asks:

If there are two defenders (one of whom is the goalkeeper) inside the goal area and an attacker scores with no other defending player in front of the attacker, is that a valid goal or is the attacker offside?

Answer (see “Apology” special note posted July 5)

We have no idea.  Your question is unclear as to what is meant by “no other defending player in front of the attacker.”  Do you mean that there were no defenders at all (including either of the two defenders, one of whom is the goalkeeper) in front of the attacker?  Or do you mean the “two defenders … inside the goal area” may or may not be in front of the attacker but there were no other defenders in front of the attacker?  Also a problem is that we don’t know where this attacker was when the attacker’s teammate touched/played the ball.  Even if the space in front of the attacker was totally devoid of all defenders at the time the attacker shot the ball into the goal, the attacker would not be in an offside position and thus able to commit an offside offense if the attacker was somewhere else (behind two or more defenders) when the attacker’s teammate last touched/played the ball.

It sounds like we are being picky but the offside position and the offside offense are chock full of picky issues and we have to be very exact as to where players were at the moment a play began rather than where the play ended.  Offside position is established at a specific moment of time but an offside offense can occur anytime thereafter until the play which started it all is over.

Offside, Throw-Ins, and the Problem with “Directly”

Greg, a referee of youth players, asks:

Red team is attacking… Red player makes a throw in. The ball strikes a Blue defender and is deflected to a Red player in an offside position. Is this an offside offence?

Offside was flagged … During the debrief after the game, I asserted that an offside offense cannot be called on a throw in. They (both AR and CR) asserted that it was a case of being in a position that gave advantage by way of “rebound” off an opponent. What’s the proper call?

Answer

What follows will likely cause some debate (flames will be ignored)and gnashing of teeth but the weight of opinion (which we join) is that there was not an offside violation.  The language in Law 11 is very simple — “There is no offside offense if a player receives the ball directly from … a throw-in.”  Every one of these words is ordinary, uncomplicated, and generally well understood — except one, “directly,” which is found numerous places in the Laws of the Game.  Every other place (e.g., Law 13 on free kicks, Law 8 on kick-offs and dropped balls, and so forth) has a specific context which involves the scoring of goals.  For example, a goal cannot be scored directly against the kicking team on a kick-off, free kick, goal kick, or a corner kick (although Law 14 does not say so specifically, it is generally assumed this also holds true for a penalty kick).  A goal cannot be scored directly against either team on a throw-in or a dropped ball.

However, with Law 11, the context is different.  Here, the concept of “directly” gets a bit more complicated because it carries one meaning when used in conjunction with offside position and another when used with offside offense, and neither one is related to the scoring of a goal, at least not directly [grin].  “Directly” has a long history in the Laws of the Game and in almost all cases means “no intervening touch or play of the ball.”  A team given, say, an indirect free kick cannot score a goal directly from this restart but, instead, hopes that the ball, in the process of moving from the kick to the goal, makes contact with someone … anyone (who is legally positioned anyway) … because then the goal will count.  This is why the attacking team with an IFK within a short distance from the opponents’ goal will attempt to power the kick through the wall and any other players in the hope that it will clip someone on the way in, thus leading to a goal.

In the case of Law 11, intervening contacts are important only if they involve a defender and the critical question is whether the contact is a “play” (briefly, “possessed and controlled”) or a deflection/rebound.  If the decision is that the ball merely rebounded (deflected, bounced off, touched but not directed) from the defender or was deliberately “saved” by a defender, then any attacker who was in an offside position at the start of this segment of play (which began when the attacker’s teammate last played the ball) is still in an offside position and thus is not allowed to become involved in active play.  In brief,  the intervention is treated as though it hadn’t happened.

The language in Law 11 which we quoted above, however, deals with an offside offense.  It posits a teammate of the thrower who was in an offside position and then declares that this position does not matter because there would be no offside offense even if that attacker in the offside position became involved in active play … directly from the throw-in.  Now we come to the meat of the matter and, ironically, the nature of the intervening contact by the opponent turns out not to make any difference.  If the contact was judged to be a play by that defender (possessed and controlled), then this ushers in a new play segment in which possession of the ball has changed teams so the teammate of the thrower is no longer even in an offside position (and therefore cannot commit an offside offense).  If the contact was judged to be a rebound/deflection (which is what is implied fairly clearly in the question), then it remains the “same play” — i.e., as though the contact never happened — and the teammate of the thrower is still in an offside position but Law 11 says that this teammate, even though in an offside position, cannot commit an offside offense.

Offside … Once Again (with Gusto)

Robb, a parent of a youth player, asks:

An attacker (Red #7) was in an offside position when her teammate (Red #11) tried to pass her the ball. It was intercepted by a defender (Blue #42) who attempted to clear the ball forward. The defender (Blue #42) kicked the ball forward but it hit the back of another defender (Blue #33) in front of her and deflected backwards to the attacker (Red #7) still in an offside position. The attacker (Red #7) subsequently scored a goal,which the Referee allowed. The Referee explained the goal would only not have counted if the deflection was off an attacker but, since the deflection was off a defender, it counts. Should a goal have been awarded? What if the deflection had been off of the referee (a neutral person on the field)? [We have added specific player team/number designations to this scenario only after discovering in the initial draft of the answer that it was going to be difficult keeping these people straight as things shifted around.]

Answer

It’s always interesting when anyone, much less a Referee, gets it right but for the wrong reason!  We are going to use the plain and usual meaning of the words in the above scenario to make a critical decision — if a defender “intercepted” the ball and then “attempted to clear the ball forward,” then it seems inescapable that this defender deliberately possessed and controlled the ball.  It wasn’t an accident, it wasn’t a deflection, it wasn’t a rebound … it was a play of the ball.  Period.

Once we get this, all the rest follows.  The moment Blue #42 played the ball, the play that had been initiated by Red #11 (which resulted in Red #7 being labeled as in an offside position) was over.  Now, this new play by Blue #42 automatically converted her into an attacker, thus making Red #7 a defender)!  Sounds crazy, yes?  But that is the way Law 11 works.

So, by definition, Red #7 is no longer in an offside position (contrary to the scenario language).  And Red #7, who used to be in an offside position but now isn’t, receives the ball from off the back of Blue #33  and then scores against Blue.  How could this possibly be an offside violation?  The goal was scored by Red #7, an attacker, who received the ball from an opponent  (Blue #33).  Offside and onside positions are determined only by looking at where attackers are at the moment the ball was last touched or played by a teammate, not by an opponent.

Accordingly, the Referee was correct to accept the goal as legally scored.  Where the Referee went astray (or, alternately, was not understood correctly) is in explaining the decision based on an irrelevant fact — namely, the ball having come to Red #7 by a deflection off the back of Blue #33.  There is a kernel of truth in the concept, but it applies only to an attacker whose last contact with the ball was accidental or a deflection and, as a result, the ball goes to a teammate.  In short, determining who is or is not in an offside position can be based on purely accidental contact with the ball by an attacker.  Applied to a defender, the exact opposite is true.  In order for Red #7 to be considered still in an offside position following intervening contact with the ball by any defender, that contact has to be accidental, i.e., not a deliberate play (or a deliberate save), but the only contact that was accidental was the deflection from Blue #33 after Blue #42 had turned herself and all her teammates into attackers by her deliberate play of the ball.  Red #7’s goal was safe for two reasons — first, Blue #42 deliberately played the ball and, second, Blue #33 wasn’t a teammate of Red #7.

More on Offside

Keith, an adult amateur coach, asks:

A player on the Red team attempts to pass the ball to another player on the Red team who is in an offside position. A player from the Blue team intercepts the pass and begins dribbling down the field. The player from the Red team who was in an offside position comes back and challenges the player on the Blue team for the ball.  Is play stopped for an offside offense?

Answer

It would be a grievous error if any official decided this was an offside offense.  This scenario is fairly fundamental and simple as regards the concepts of offside position and offside offense.  For simplicity’s sake, lets call the initiating player Red #5, his or her teammate Red #19, and the defender Blue #45.  Now, break this thing down.

First, when Red #5 played the ball, that established which (if any) teammates were in an offside position and which (if any) were not.  Your scenario declares that Red #19 was in an offside position, presumably by virtue of being, at that specific moment, past the ball, the midfield line, and the 2nd to last defender.  No offense has yet been committed.

Second, between Red #5’s contact with the ball and Blue #45’s subsequent contact with the ball, did Red #15 do anything that constituted “becoming involved in active play” — interfering with play, interfering with an opponent, or gaining an advantage by his or her position?  Nothing in the scenario suggests this happened and thus, prior to Blue #45’s intervention, no offside violation was committed by the only Red player we are told was in an offside position and thus whose play of the ball was restricted  by Law 11.

Third, Blue #45 made contact with the ball.  This is the critical point.  Merely “making contact with the ball” does not necessarily change anything but, in this case, the scenario’s wording  (“intercepts the pass and begins dribbling down the field”) makes it crystal clear that Blue #45 has, in fact, deliberately played the ball.  At this moment, Red #15 (and any other Red attacker who might also have been in an offside position when their teammate made contact with the ball) ceased to be in an offside position.

In short, the world got turned upside down.  Defenders (Blue) are now attackers and attackers (Red) are now defenders and, for as long as this play continues past Blue #45’s intervention and the ball stays in possession of the Blue team, no Red player can be in an offside position and thus could not under any circumstances commit an offside offense.  Now that Blue #45 has deliberately played the ball, only Blue players can be in an offside position and the possibility of a Red player committing an offside offense is, flatly, nil.

Would that life were always so simple.  The critical point was Blue #45’s contact with the ball and the decision that has to be made here is whether that contact constituted a deliberate play.  Here it did and so the decision is easy.  Change any one of the elements of that contact and the decision could become more difficult.

But that is for another question and answer ….

Offside and Playing the Ball

A referee asks:

Player A1 kicks the ball.  Player B1 heads the ball and it falls directly to player A2 who is standing in an offside position.  Is Player A2 offside?

Answer

Whenever we discuss anything pertaining to an offside question, it’s always useful to make sure we are speaking the same language.  Your basic question is “Is Player A2 offside?” and our first response is “What do you mean by ‘offside’?”  Law 11 uses the term to mean two related but very different things.  If by “offside” you mean “offside position,” then clearly the answer is “yes” because this is a given in your scenario but, as we all know, there is nothing illegal or immoral about being in an offside position.   Our next question therefore is “So what?”

The challenge for an offside position player is to not become involved in active play while carrying that tag.  If you do, then you have committed an “offside violation” and an offside violation involves a whole different set of issues.

If A1 had kicked the ball directly (which, in soccer, means only that there was no intervening touch or play of the ball by anyone else) to A2, we still do not necessarily have an offside violation because A2, before being whistled, needs to become involved in active play.  To say that the ball “falls … to A2” indicates nothing more than that the ball wound up from A1’s play somewhere at or near A2 and it says nothing about what A2 did about this.  Did A2 then make contact with the ball, which is at the core of “becoming involved in active play by interfering with play”?  At this point, A2 could play the ball (violation) … or A2 could make eye contact with the referee and begin backing away while shouting to his teammates “No!  I can’t play the ball.” (no violation).

Your scenario, however, adds a twist.  The ball off A1 didn’t go directly to A2 — there was an intercepting contact with the ball and, in fact, it was by an opponent.  If, instead, the interception had been by a teammate (A3) in an onside position, then there would be no offside violation and thus ends that particular segment of play for offside analysis, only to begin another when A3 heads the ball to A2.  Was A2 still in an offside position at the time A3 headed the ball?  Did A2 then become involved in active play by touching the ball in any way?  If the answers to both questions is “Yes,” then there has been an offside violation; if the answer to either of these questions is “No,” then no offside violation.  (For purposes of this scenario, we’re focusing on “interfering with play” and not such additional ways of active play involvement as “interfering with an opponent.”)

So, we come to the heart of your scenario and the really important question becomes “What do you mean by ‘heads’?”   In an offside scenario involving intervening contact with the ball by an opponent (B1), the referee must decide whether the contact was deliberate or accidental (e.g., a deflection off the opponent’s head, trunk, or legs).  If deliberate, then there is no violation because, by the deliberate play, the opponent took possession of the ball and, when that ball then went to A2, it was no longer coming from A2’s teammate.  If accidental, then there is a violation because the accidental contact is deemed not to have given B1 possession and, thus, the ball at A2’s feet had indeed come from A1.

There are one note and two important caveats to remember in all this.

The note is that, historically, this distinction between deliberate and accidental applies only to a defender, not to an attacker.  In other words, any contact with the ball by an attacker, without regard to whether it was accidental or deliberate, is deemed as “coming from the attacker” for purposes of evaluating the offside position.  A rather extreme example of this might start with both A2 and A3 in onside positions but with A2 moving forward toward the opponent’s goal.  The ball is struck toward the intended target A3 by A1 and it glances of A3’s head.  Since A3 was in an onside position when A1 kicks the ball, there is no violation.  The glance of the ball redirects it to A2 who, at the time of the glance, had moved far enough toward the opposing goal line that A2 is now in an offside position.  There is an offside violation now if A2 interferes with play because, although not in an offside position when A1 kicked the ball, A2 is in an offside position when the ball accidentally deflects off A3.  The accidental deflection is treated the same as a deliberate play.

The first caveat is that the decision about whether B1’s contact was deliberate or accidental is solely in the opinion of the referee.  There are no hard and fast guidelines for this — you have to “be there” to see all the facts and circumstances.  That said,  using the phrase “heads the ball” generally suggests a deliberate play.

The second caveat is that there is a significant exception to the whole deliberate/accidental dichotomy — namely, it doesn’t matter even if the contact was deliberate if the opponent’s resulting play is deemed to be a “save”!  The 2016/2017 rewrite of Law 11 requires us to develop some general notion of what a “save” is.  Fortunately, the Law has given us an excellent start on this by defining a “save” (p. 166, current Lawbook) as “an action to stop the ball when it is going into or very close to the goal.”  “Into the goal” is easy … this has long been meant as “but for the intervention, the ball would have gone into the net.”  “Or very close” is tougher but could be thought of as “so close to looking like it would go into the goal that a reasonable defender would expend every legal effort to prevent the goal” — some might think of this notion as meaning something desperate enough to be virtually reflexive (e.g., a goalkeeper fisting the ball away).

So, finally, we can answer your question about whether A2’s actions constituted an offside violation.  “Yes” if “heads” is pictured as an accidental deflection, “No” if the referee decides B1’s play was deliberate, and “No” if the accidental deflection was a save.