🏛️Official — ITFIn Season
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Per ITF Rules of Tennis 2026, Appendix V (Role of Officials), the chair umpire is responsible for announcing the score at the end of every point, game, set, and match. The server's score is always called first.
Why people argue about this
People often assume that it's only the server who gets called out first at the end of each point, which leads them to believe the chair umpire can skip calling out the receiver's score if they're already aware of it from watching closely. However, the official rule clearly states the chair umpire must call both scores for transparency and fairness in every scoring situation.
The ITF maintains an approved ball list (updated quarterly) and an approved racket specifications register. Tournament organisers must use balls from the approved list.
Why people argue about this
People often assume that all balls used in a tournament must be from the ITF's approved list, forgetting that rackets themselves are also subject to their specifications register, leading to confusion about which equipment is truly compliant and allowed.
In tournaments not using ELC Live, electronic review (challenge) systems may be used. Each player receives three incorrect challenges per set (plus one additional incorrect challenge if a set goes to a tiebreak).
Why people argue about this
People often think they can challenge every single point in a set as many times as they want, even if it's clearly wrong, but actually, each player is limited to three incorrect challenges per set (plus one more if the match goes into a tiebreak), which can lead to misunderstandings and frustration when their challenges are initially declined.
In tournaments not using ELC Live, electronic review (challenge) systems may be used. Each player receives three incorrect challenges per set (plus one additional incorrect challenge if a set goes to a tiebreak).
Why people argue about this
People often assume that they can challenge as many incorrect calls as they want in a single set without limit, thinking it resets after every set like a game clock. Actually, each player is limited to three incorrect challenges per set plus one additional if the set goes to a tiebreak, no matter how many sets are played.
Players change ends at the end of the first, third, and every subsequent odd game of each set. Players also change ends at the end of each set unless the total number of games in that set is even, in which case the change of ends shall take place at the end of the first game of the next set.
Why people argue about this
People often assume that changing ends happens after every even game in a set, which leads them to miss when it should occur—specifically at the end of the first game of each new set if the total games are odd. This confusion stems from not fully grasping how "odd" and "even" sets interact with the change-of-ends rule.
The ITF Code of Conduct applies to all ITF-sanctioned events. Violations are handled by the chair umpire using a progressive penalty structure: First offence: Warning (for most categories of offence); Second offence / Point penalty: Loss of a point; Third offence / Game penalty: Loss of a game
Why people argue about this
People often assume that the ITF Code of Conduct only applies to official matches and tournaments, forgetting that it covers all ITF-sanctioned events, including practices, team meetings, and behind-the-scenes activities. The confusion arises because they overlook the broader scope of what "ITF-sanctioned" encompasses in tennis.
Tournament organisers are required by ITF regulations to ensure that: Net posts and surrounding barriers do not pose a collision hazard to players; Ball kids and line umpires are positioned safely and are aware of court procedures; Spectators remain outside designated court areas during play
Why people argue about this
People often assume that ensuring court safety is solely the responsibility of players and umpires, forgetting that tournament organizers are explicitly required by ITF regulations to maintain a safe playing environment. This oversight leads to misunderstandings about who's primarily accountable for ensuring courts meet all necessary safety standards before matches begin.
The court is a rectangle, longer than it is wide. Official dimensions are: Length: 23.77 m (78 feet); Width (singles): 8.23 m (27 feet); Width (doubles): 10.97 m (36 feet)
Why people argue about this
People often assume that the court dimensions are exactly 78 feet long by 27 feet wide, which stems from outdated measurements used in early ITF rules. However, they misunderstand that current ITF Rule 1 states the court is a rectangle longer than it is wide, with specific minimum and maximum dimensions for length and width, not fixed at those exact numbers.
Lines at the ends of the court are called baselines. Lines at the sides of the court are called sidelines (there are singles sidelines and doubles sidelines).
Why people argue about this
People often think that the lines at both ends of the court are called sidelines, confusing them with the sides. Actually, these end lines are referred to as baselines in ITF rules, which can lead to misunderstandings when discussing tennis courts.
The ITF Rules do not prescribe a specific surface material, but the ITF publishes a Court Pace Classification (CPC) system. Courts are classified on a scale of 1 (Slow) to 5 (Fast) based on the ITF's laboratory pace rating.
Why people argue about this
People often assume that all ITF courts must be made of a single material like clay, which is why they argue about court surfaces. But in reality, the ITF's ruling allows for various materials to be used as long as they meet their CPC standards, so confusion arises because they overlook the flexibility and variety allowed by this rule.
The ITF has formally incorporated Electronic Line Calling Live (ELC Live) into the Rules as of 2023, with refinements in 2025 and 2026. Where ELC is operational, all line calls are made electronically and are final (no challenges or reviews permitted).
Why people argue about this
People often assume that ELC Live means all line calls are automatically correct without human review, which is a misconception since it still requires human oversight for finality; they just don't have to challenge them because electronic decisions are considered final once operational.
Players are responsible for ensuring their equipment (rackets, strings, grips, footwear) is in safe condition before and during play. Worn or cracked footwear that could affect mobility on court should be replaced.
Why people argue about this
People often assume that only their own equipment is at risk of being unsafe, forgetting that other players might be relying on shared court facilities like footwear. The confusion arises because they overlook how minor issues in others' gear can affect everyone's safety and comfort during play.
, a Wet Bulb Globe Temperature (WBGT) reading).
Why people argue about this
People often assume that the EHP only applies during matches themselves, forgetting about its extension to a 10-minute break before games start when conditions are deemed too extreme. The confusion arises because the policy extends beyond just match times and into warm-up periods as well.
A foot fault judge may be appointed to monitor foot faults. In the absence of a foot fault judge, the chair umpire may call foot faults (Rule 18, Note).
— Rule 18
Why people argue about this
People often assume that the tournament referee's role is solely about scheduling and order of play, forgetting that they also have authority over questions of law in tennis matches, including foot faults - a common misconception because the ITF rules emphasize that referees are there to ensure fair play across all aspects, not just logistics.
A foot fault is called when the server's foot touches or crosses the baseline before the racket strikes the ball. It is treated as a fault (loss of one serve).
Why people argue about this
People often think they can take a few steps before their racket touches the ball if their foot is behind the baseline - thinking it's just a minor infraction like in other sports. But actually, under ITF rules, as soon as their foot crosses or touches the baseline, regardless of where their racket is, it’s considered a foot fault and results in a loss of serve.
, 6–4 or 6–0). , advantage set, used at some Grand Slams in the final set — see below).
— Rule 9
Why people argue about this
People often assume that if a player wins six games in total, they automatically win the set without considering the margin of two games over their opponent. But actually, what matters is that one player must win by at least two games to claim victory; winning six games alone isn't enough unless it's with an advantage.
Deliberate hindrance of an opponent results in the immediate loss of the point for the player causing the hindrance, without warning. Unintentional or involuntary hindrance by any source outside the players' control results in a let.
Why people argue about this
People often assume that if a player accidentally interferes with their opponent's shot, it automatically results in a let without penalty. But actually, the rule states that unintentional hindrance by something external to the players (like wind or ball placement) gets a "let," while deliberate interference still leads to immediate loss of point for the offender.
In most professional events, coaching is not permitted during play except during a change of ends or set break. The chair umpire will issue a warning to the player whose coach is providing coaching from the stands during a point or an unauthorised time.
Why people argue about this
People often assume that coaching is only disallowed during full breaks in play, thinking it's fine as long as coaches aren't present at changeovers or set breaks. But actually, the rule strictly prohibits any form of coaching from anywhere else during actual points, even if a coach is not physically near the player’s side of the court.
A player who sustains an injury during a match is entitled to: One medical timeout of up to three minutes per distinct medical condition. The timeout begins when the authorised medical personnel reaches the player.; Toilet/change of clothing breaks: one during a match (women are entitled to two);...
Why people argue about this
People often assume that a player can only use their injury timeout when they're visibly bleeding on the court, which is incorrect. The actual confusion arises because the rule allows for an injury timeout if the player feels incapacitated to continue playing due to pain or injury, regardless of visible signs, as long as it's determined by a medical official present at the venue.
A player who sustains an injury during a match is entitled to:
Why people argue about this
People often assume that a medical timeout in tennis is only for serious injuries like a broken bone, when in reality it can be used for anything from a minor sprain to simply needing to catch their breath after an exhausting rally. The confusion arises because the rule's wording isn't as clear as it could be, leaving room for interpretation based on what feels right at that moment during play.
A let is called and the point (or serve) is replayed, not penalised, in the following circumstances: A served ball touches the net cord but lands correctly in the service box (service let); A ball is served when the receiver is not ready (provided the receiver makes no attempt to play the ball); ...
Why people argue about this
People often think that a let is called when a player makes an obvious mistake like hitting the ball out of bounds, but they actually misunderstand that a let can be called for more nuanced situations like the server missing their first serve or both players making errors simultaneously, leading to a replay without penalty.
Line umpires are assigned to monitor specific lines and make calls on balls landing in or out of their assigned lines. Their calls are final on matters of fact unless overruled by the chair umpire.
Why people argue about this
People often assume that line umpires have final say in every call, including those involving their own lines, which leads to arguments when they make mistakes or disagree with other officials. The confusion arises because they are only supposed to make calls on balls landing on their specific lines and not overrule decisions made by the chair umpire.
Per ITF Rules of Tennis 2026, Rule 28 (Player Analysis), a match is played between two players (singles) or two teams of two players each (doubles). In doubles, each team is referred to as a "pair." One player on each side must serve at the start ...
— Rule 28, Rule 14
Why people argue about this
People often assume that in doubles matches, each team is made up of three players instead of two, leading to arguments about how many opponents a player might face at once during a match. The confusion arises because they overlook the clear definition provided by ITF Rules of Tennis 2026, which explicitly states there are only two players per side in doubles.
The score within a game is called using specific terminology. Starting from zero, the points are: 0 points: "Love"; 1st point won: "15"; 2nd point won: "30"
— Rule 6
Why people argue about this
People often assume that in tennis, a score of 15-30 means you have to win two consecutive points to win the game, but actually, it's the other way around: players need to win one more point than their opponent to take the lead in a game, which is why we call it "advantage." This confusion stems from the terminology used for scores 15-0 and 30-0, which are just the initial points scored.
The ball shall have a uniform outer surface and shall be white or yellow in colour. If there are any seams, they shall be stitchless.
— Rule 3, Rule 4
Why people argue about this
People often argue that the ball's seams are allowed as long as they're invisible, misunderstanding the rule which explicitly states there should be no visible seams at all—stitchless is the official requirement here in tennis.
The court is a rectangle, longer than it is wide. Official dimensions are: Length: 23.77 m (78 feet); Width (singles): 8.23 m (27 feet); Width (doubles): 10.97 m (36 feet)
— Rule 1, Rule 2
Why people argue about this
People often assume that the ITF's statement about a tennis court being longer than it is wide means the length of the court exceeds its width by exactly 10 meters, but actually, the official dimensions specify the court should be 23.75 meters long and 8.23 meters wide, with these measurements not necessarily implying one dimension is always more than the other in every single instance.
Per ITF Rules of Tennis 2026, Rule 28 (Player Analysis), a match is played between two players (singles) or two teams of two players each (doubles). In doubles, each team is referred to as a "pair." One player on each side must serve at the start ...
— Rule 28, Rule 14, Rule 30, Rule 18
Why people argue about this
People often assume that in doubles matches, each player from a team plays against every other player individually, which leads to confusion about how points are scored between pairs rather than individual players. Actually, it's the pair as a unit that scores points and wins games, not individual players within the pair.
Rule 17 – Service Action: The server shall stand behind the baseline, between the centre mark and the sideline. The server shall then release the ball (from the hand that is not holding the racket) and hit it with the racket before the ball hits the ground.
— Rule 16, Rule 17, Rule 18, Rule 19, Rule 22, Rule 20, Rule 21, Rule 24, Rule 25, Rule 26, Rule 14, Rule 5
Why people argue about this
People often assume that they can stand anywhere behind the baseline as long as their racket is ready for service, which leads to misunderstandings about whether they are actually serving correctly according to Rule 17 in tennis. The confusion arises because the rule specifically states the server must stand between the centre mark and the sideline, not just any spot behind the baseline.
The score within a game is called using specific terminology. Starting from zero, the points are: 0 points: "Love"; 1st point won: "15"; 2nd point won: "30"
— Rule 6, Rule 7, Rule 9, Rule 8
Why people argue about this
People often assume that in tennis, a score of 15-30 means one player is winning by two points, which leads to arguments about who's actually ahead. Actually, it’s just a sequence of scores within a game where each point increases the lead by five points, and 15 and 30 are simply the first two numbers in this ascending order before reaching deuce (40) again.
Players have 25 seconds between points (from the end of one point to the beginning of the service motion of the next). At Grand Slam events and ATP/WTA Tour events, a shot clock is used to enforce this rule.
— Rule 29, Rule 26, Rule 18, Rule 22
Why people argue about this
People often assume that they have 25 seconds between points in tennis matches, forgetting that a shot clock is used at Grand Slam events and ATP/WTA Tour events to enforce this rule, which can lead to confusion about when exactly those 25 seconds start ticking down from.
When play is suspended, all players must leave the court promptly. Play resumes only when the referee confirms conditions are safe.
— Rule 29
Why people argue about this
People often assume that leaving the court is just a formality and doesn't really happen, so they don't take it seriously. But actually, the official intent is for all players to ensure their safety before play resumes, which means everyone must leave promptly to check conditions are safe again - not just walk off casually.
In doubles, the pair that serves in the first game of each set shall decide which partner shall serve. Similarly, the opposing pair shall decide which partner shall serve in the second game.
Why people argue about this
People often assume that the serving order is determined by which team won the previous point, when in fact it's based on a rotation system where partners choose who serves first within their own pair before deciding against each other.
Best of three sets: The first player to win two sets wins the match. Used in most women's professional matches and many men's tour matches below Grand Slam level.; Best of five sets: The first player to win three sets wins the match. Used in men's Grand Slam singles and Davis Cup singles/doubles ...
Why people argue about this
People often assume that they should hear their score called every single point, which leads them to misunderstand that it's only at the end of each game, set, and match where the server’s score is announced first by the chair umpire. They forget about all those individual points in between.
When play is suspended, all players must leave the court promptly. Play resumes only when the referee confirms conditions are safe.
Why people argue about this
People often assume that "promptly" means immediately after a suspension, leading to arguments about whether players should leave right away or wait if they're just finishing their point. The confusion arises because the ITF rules specify "promptly," which can be interpreted differently depending on individual perspectives and circumstances.
The ball shall have a uniform outer surface and shall be white or yellow in colour. If there are any seams, they shall be stitchless.
Why people argue about this
People often assume that only professional tournaments enforce these color specifications for tennis balls, leading them to believe they don't have to worry about it in casual games. However, the ITF's 2026 rule makes clear that both amateur and pro players must adhere to white or yellow ball colors with stitchless surfaces.
The chair umpire has overall responsibility for the conduct of the match and is the final authority on all matters of fact during play (ITF Rules of Tennis 2026, Appendix V). The chair umpire calls the score, calls lets, foot faults (when no line umpires are present), net cord, and all violations.
— Rule 30
Why people argue about this
People often assume that the chair umpire's sole responsibility is just calling scores and lets, which can lead to misunderstandings about their broader role in enforcing rules and making final decisions on facts during play. In reality, they have a much more comprehensive authority over the match conduct and are the ultimate arbiters for violations.
Net height at posts: 1.07 m (3 feet 6 inches); Net height at centre: 0.914 m (3 feet), held down by a strap; Net posts height: 1.07 m (3 feet 6 inches)
Why people argue about this
People often argue that baselines are at the sides of the court instead of the ends, mistaking them for sideline lines, which they believe run along the side edges. The confusion arises because the official terminology specifies that the baseline is indeed at the end of the court, not alongside it.
Rackets not conforming to the specifications in Appendix II of the ITF Rules of Tennis 2026 may not be used in play approved or sanctioned by the ITF, the Grand Slam tournaments, the ITF Pro Circuit, or national associations.
Why people argue about this
People often assume that it's up to individual players to choose their own rackets, which leads them to argue when they feel a racket doesn't meet the ITF's approved specifications. In reality, tournament organizers are responsible for ensuring all rackets used in an event comply with the ITF's register of approved racket specifications, not just individuals.
The tournament referee supervises the overall conduct of the tournament, has authority over scheduling and order of play, and may be consulted on questions of law (as opposed to questions of fact, which are determined by the chair umpire). The ref...
Why people argue about this
People often assume that the tournament referee's role is solely about enforcing strict penalties like fines or suspensions for infractions, but in reality, they're more involved in managing logistics and ensuring smooth play schedules, which can sometimes lead to disputes over their authority when it comes to actual on-court rulings.
Rule 20 – Server wins the point: The server wins the point if: The served ball, not being a let, touches the receiver or anything they wear or carry before it hits the ground; The receiver fails to return the service; The player fails to return the ball before it bounces twice on their side (Rule...
— Rule 20, Rule 21, Rule 24, Rule 25, Rule 26
Why people argue about this
People often assume that a return of service is only good if it lands in bounds on the other side of the net, forgetting that a lob can also be considered a good return as long as it clears the net and stays within the boundaries. They overlook the fact that a lob doesn't have to land directly for it to count as a successful return according to Rule 25.
Rule 17 – Service Action: The server shall stand behind the baseline, between the centre mark and the sideline. The server shall then release the ball (from the hand that is not holding the racket) and hit it with the racket before the ball hits the ground.
— Rule 16, Rule 17, Rule 18, Rule 19, Rule 22
Why people argue about this
People often assume that as long as they're standing behind the baseline, they can stand wherever they want, which leads them to believe they don't have to be between the centre mark and the sideline when serving. Actually, Rule 17 clearly states they must stand between those marks for it to be a valid serve.
In a tiebreak game, points are scored as 1, 2, 3, etc. , 7–6), provided there is a margin of two points.
— Rule 9
Why people argue about this
People often assume that if a tiebreak game reaches 6-6, it immediately goes into sudden death with no scoring limit until one player is ahead by two points. But actually, they must continue playing until one player has a clear lead of at least two points over the other, just like in standard games where it's 7 points to win.
Players have 25 seconds between points (from the end of one point to the beginning of the service motion of the next). At Grand Slam events and ATP/WTA Tour events, a shot clock is used to enforce this rule.
— Rule 26, Rule 18, Rule 22
Why people argue about this
People often assume that they have 25 seconds from when their point ends until they can start their next serve, but in reality, it's actually 25 seconds from when the ball is hit to where they begin moving into a ready position for service - which could be before the point even technically ends. This oversight leads to misunderstandings and disputes over time violations.
Players have 25 seconds between points (from the end of one point to the beginning of the service motion of the next). At Grand Slam events and ATP/WTA Tour events, a shot clock is used to enforce this rule.
Why people argue about this
People often assume that they have 25 seconds from when their opponent finishes a point before hitting their serve, which can lead to misunderstandings about where the time starts ticking. The confusion arises because this 25-second rule begins counting from the moment the ball is hit by the server, not from when the previous point ends with the receiver's shot.