What is a defensive foul in basketball
A defensive foul is an infraction that occurs during a basketball game when a defender uses any part of their body such as their hands, arms, legs, or feet to make illegal contact with an opposing offensive player.
What is notable information about legal guarding position in relation to defensive foul
It is important to note that when a defender makes illegal contact with an opponent, this also means the defender has not established and/or maintained a legal guarding position.
From that point, once a legal guarding position has not been established or maintained and that is combined with illegal contact, the result for the defender is effectively a defensive foul.
Establishing initial legal guarding position
Generally speaking, when both of a defender’s feet are on the playing court and that defender faces their opponent, particularly with their torso, that is the establishment of initial legal guarding position.
Additionally, when an offensive player has possession of the basketball, a defender who established legal guarding position is not required to give time and distance.
That is to say, the offensive player with the ball should expect to be guarded and therefore has to be ready to stop their own movement or change direction whenever a defender establishes an initial legal guarding position.
This applies even if the defender takes that legal guarding position within a fraction of a second.
Otherwise, if the offensive player commits illegal contact with a legally guarding defender, then that action could lead to an offensive foul as opposed to a defensive one.
Conversely though, when an offensive player does not have possession of the ball, the defender has to give the opponent enough time and distance to avoid contact.
The time and distance required to be given is usually only a step or no more than two strides.
Ultimately, if a defender does not establish initial legal guarding position, then that same player could be assessed a defensive foul when there is illegal contact that happens beyond the defender’s own occupied space.
It should also be mentioned that the defender’s occupied space consists of an imaginary cylinder that surrounds that player from the floor to as far as they can jump or extend their arms above their head.
Furthermore, it is important to note as well that the imaginary cylinder applies to an offensive player as well and its diameter does not extend beyond any particular player’s hands/arms on the front side, a player’s rear on the back side, or the sides of a player’s legs.
Nevertheless, a cylinder’s dimensions may change depending on the height and size of a player.
Maintaining legal guarding position
To maintain legal guarding position after the initial establishment, the defender does not need to keep their torso directly facing the opponent.
Moreover, a defender could maintain legal guarding position while sliding their feet in the pathway of a dribbling offensive player prior to contact or by generally moving their feet laterally, backwards, or at angles.
However, the defender cannot move forward into an offensive player, especially while that opponent is dribbling the basketball as that would most likely lead to a defensive foul assessment by the referee.
The defender is also required to establish and maintain legal guarding position before an offensive player initiates an upward motion in the air, which is primarily utilized for a field goal attempt.
Otherwise, the defender could get charged with a defensive foul for illegal contact against the offensive player.
Additionally, a defender could maintain legal guarding position while jumping in the air and raising their hands directly above them within their own vertical plane, which also includes their imaginary cylinder.
Nonetheless, the defender cannot extend their arms, shoulders, hips, or legs outside of their cylinder, especially to stop the offensive player from blowing by or cutting by them, with or without the basketball respectively.
If that were to happen, then the defender would most likely be charged with a defensive foul because of illegal contact with the opposing offensive player.
It should also be noted that if contact from an offensive player in possession of the ball is imminent, a defender is allowed to put their hands and/or arms in front of their face or body to absorb the shock from that contact and/or to generally avoid injury.
In that case, the defender will most likely not be assessed a defensive foul, assuming that player remained within their own cylinder during the moment of contact.
Instead, the offensive player would most likely be called for a charging foul because the defender, still within their cylinder, maintains legal guarding position while the offensive player does not.
What are examples of player actions that typically lead to a defensive foul
Defender checks opponent with hand
Hand checking occurs when a defender makes illegal contact, mainly by inhibiting an opponent’s speed, quickness, balance, or rhythm with one or both hands.
When a defender hand checks, they are no longer establishing/maintaining a legal guarding position and are therefore liable to receiving a defensive foul assessment from a referee.
Related: Illegal Contact, hand check, defender affects dribbler’s SQBR – NBA Video Rulebook
Defender bumps opponent with body
Body bumping, sometimes called body checking, occurs when a defender makes illegal body contact, usually with their torso or hips to inhibit the opponent’s speed, quickness, balance, or rhythm.
When a defender uses their body to bump an opponent’s body, they are no longer establishing/maintaining a legal guarding position and are therefore liable to receiving a defensive foul assessment from a referee.
Related: Illegal Contact, body bump, affects SQBR – NBA Video Rulebook
Defender pushes opponent
If a defender uses one or both hands to push an offensive player in the front area or back area, then that would be a defensive foul via illegal contact.
Also, if a defender uses one or both hands to push away the arm of an opponent with or without possession of the basketball, that would represent a defensive foul as well.
Defender makes illegal contact after reaching in
Reaching in, sometimes colloquially known as a reach in foul, occurs when an on-ball defender makes illegal contact with an opponent while attempting to steal the ball.
Essentially, when a defender attempts to steal the ball by reaching in from their own cylinder into the opponent’s cylinder but in that process, the defender happens to make illegal contact with the opponent, this is no longer a legal guarding position.
From there, once the defender is no longer in a legal guarding position and that is combined with the illegal contact, the result is a defensive foul.
Defender goes over the back of opponent
When a defender is being potentially boxed out by an opponent who is in a legal rebounding position and that defender makes illegal contact, particularly by jumping over the back of that opponent in an attempt to collect a rebound, it is a defensive foul.
Defender makes illegal contact while opponent is in the act of shooting
When a defender makes illegal contact while an opponent is in the act of shooting the ball, it is effectively a defensive foul.
It should also be mentioned that this particular type of defensive foul is known as a foul in the act of shooting or simply, a shooting foul.
Additionally, if a defender does not necessarily commit illegal contact during an opponent’s jump shot release but immediately afterwards, the defender does not give the opponent enough space to safely land on the floor, then this would still constitute a defensive foul.
Related: Foul in the act of shooting, up fake and contact, shooter jumps to the rim – NBA Video Rulebook
Related: Defensive foul, defender doesn’t allow shooter room to land – NBA Video Rulebook
Defender makes illegal contact by impeding opponent’s progress
When a defender makes illegal contact, particularly to impede or stop an opponent’s progress towards a certain area on the court, it is a defensive foul.
This usually occurs when a defender tries to beat an opponent, with or without the basketball, to a spot on the floor. However, the defender is usually a step too slow and makes illegal contact with the opponent.
As a brief example of this, let’s say that an offensive player in possession of the basketball near the top is attempting to dribble to a certain area of the court such as the high post elbow.
At the same time, let’s also say that an on-ball defender attempts to cut off that dribble penetration by sliding into the opponent’s pathway.
However, let’s further assume that the defender is too slow and is not able to slide towards the high post elbow before the offensive player dribbles the ball into that area.
When that happens, the defender commits illegal contact by unintentionally bumping into the offensive player, which impedes the offensive player’s progress as well.
From there, the illegal contact in combination with the lack of proper legal guarding position would result in a defensive foul, which in this case, is also a blocking foul.
Related: Blocking, on-ball defender does not establish legal guarding position – NBA Video Rulebook
What are common penalties after a player gets assessed a defensive foul
Personal foul and team foul accumulation
When a player gets assessed with a defensive foul by the referee, it will be recorded, typically by the official scorer, and added to the total number of personal fouls for that player.
Additionally, the amount of team fouls will increase as well. However, it should be noted that team fouls will not increase if personal fouls are charged to one player of each team about the same time, which are also known as double fouls.
Free throw attempt(s) for the offensive player in the act of shooting
If a defender gets charged with a defensive foul while an opposing offensive player is in the act of shooting, then the penalty will be one or more free throw attempts for that same opponent.
Free throw attempt(s) for an offensive team in the bonus
If a defender makes illegal contact, which leads to a defensive foul, and at the same time, the defender’s team has reached a certain number of team fouls within a period of a basketball game, then that could trigger the bonus or penalty situation for the offensive team.
During the bonus, the offensive player who was fouled would be able to attempt one or two bonus free throws.
Sideline or baseline inbound pass while not in the act of shooting
If a defender is assessed a defensive foul against an offensive player who is not in the act of shooting, then the offensive team will commonly execute an inbound pass at a designated spot near the sideline or baseline.