87 guides · free to read
How tennis actually works.
Each guide answers one question the way a pro would: the short answer first, then the mechanism and the numbers behind it, a drill with a number to beat, and the faults that stop club players. Sources on every page.
01 Strike
How to hit harder in tennis without swinging harderTo hit harder without swinging harder, start the swing from the ground and fire the body in order: legs, hips, trunk, arm, then racquet. Each link speeds up the next and then brakes, throwing momentum outward. On the serve, the legs supply an estimated half or more of the energy. The arm is the last and smallest contributor.How to use your legs on the tennis serveTo use your legs on the serve, bend into a deep load and push the court away, then leave the ground and land on your front foot inside the baseline. The court pushes back with the same force, and that force is the budget your hips, trunk and arm spend. Elite servers push about 1.5 to 2.1 times their body weight into the ground.How to use hip and shoulder separation for a heavier forehandFor a heavier forehand, coil the shoulders against the hips on the unit turn, then fire the hips first while the shoulders hold for a beat. That stretches the trunk like a spring, and the shoulders uncoil on top of the hips' speed. A longer backswing isn't a speed source. The coil is.How to get racquet lag on your forehandYou get racquet lag on your forehand by keeping your hand soft while your body turns, so the racquet head trails your hand and then releases. Don't snap the wrist for power. In elite forehands, forearm pronation adds almost nothing to racquet speed, while the shoulder adds about 45 to 48%. The wrist's job is to get out of the way.Should you snap your wrist on the serveNo, you shouldn't try to snap your wrist on the serve. Shoulder internal rotation supplies about 40 to 54 % of racquet speed, and forearm pronation about 5 %. What looks like a snap in slow motion is the racquet face being carried round by a rotating arm. Drop the racquet edge-on and let the forearm and shoulder turn the face.How to choose a tennis racquet: weight, balance, swingweightChoose a tennis racquet by three numbers: mass, balance and swingweight. Mass is what you carry, balance is where it sits, and swingweight is what your arm feels when you swing. A lighter frame isn't automatically easier to swing. If its mass sits in the head, its swingweight can be the same or higher. Ask for swingweight.How string tension and type affect spin in tennisSpin comes mostly from string snapback, not tension. During contact the main strings slide sideways and snap back as the ball leaves, adding rotation. Slick polyester slides further than nylon and, in one test, gave roughly 20% more spin. Tension barely changes ball speed, so a steeper swing path is the bigger fix. Strings also lose tension from the first minute.Where is the sweet spot on a tennis racquetA tennis racquet has at least three sweet spots, centimetres apart. The vibration node gives the cleanest feel, the centre of percussion gives no jolt to the hand, and the maximum-rebound point gives the most ball speed. They don't coincide. Hit off-centre and the frame twists, the ball loses speed, and a shock runs to your wrist and elbow.Which tennis grip to use for your forehandThere's no single best forehand grip, but semi-western, with the base knuckle on bevel 4, is the compromise the tour settled on: more spin than eastern, better on low balls than western. The bevel sets your strike zone, from waist to shoulder at eastern to above the shoulder at western. Pick the grip for the balls you get, and change grips in the split step.How to test if your tennis balls are deadTo test a tennis ball, drop it from 254 cm and measure the rebound: by ITF rule it must come back up between 134.6 and 147.3 cm. Below that, it's outside the rule. A dead ball bounces lower and flies shorter, so practising with one grooves a swing for a ball you won't meet in a match.Why you hit the ball late in tennis, and how to fix itYou usually hit the ball late because you arrived in the wrong place, not because of your swing. The ball stays on the strings for about 4 to 5 milliseconds, too short to feel or correct. Everything you do at contact was decided before the ball arrived. Fix your spacing with your feet so contact lands in front of the lead hip.How to hit topspin in tennisTo hit topspin, swing low to high so the racquet brushes up the back of the ball with a slightly closed face, instead of driving through it. The path makes the spin, not a wrist roll: the ball has left the strings before a rolled wrist closes the face. Polyester strings add a bonus on top of whatever spin your path makes.When to hit flat and when to hit topspin in tennisHit flat when the ball is short and low and you're inside the baseline. Hit topspin when you're deep and the ball is high. One racquet-head speed buys either a flat drive or a heavy ball, never both. Tilt the swing path upward and you trade forward speed for spin, which gives you more margin but lands shorter.Why off-centre hits hurt your arm, and how to find the sweet spotOff-centre hits hurt because the frame twists and rings instead of moving back as one piece, so the ball leaves slower and the handle jolts your hand. The tendons that hold the wrist up catch that jolt, and a late backhand makes them work hardest. Fix the contact point first, then the string, then the frame.How high over the net should you hit in tennisAim at the middle of your net window, not at the line. For a topspin rally ball, that means clearing the net by about 1.5 to 2 metres and still landing deep. Spin makes that possible: it's the only ingredient that pulls the ball down without slowing it, so it widens the range of launch angles that land in.How topspin works: the Magnus effect in tennisTopspin works through the Magnus effect: a spinning ball drags air around with it, and the pressure difference pushes the ball at right angles to its spin axis. With topspin that push points down, so the ball dives. At heavy pro topspin the push is about 0.5 N, close to the ball's own 0.56 N weight. That lets you aim high, swing hard and still land it.Why topspin kicks up and slice stays low after the bounceTopspin kicks up and forward after the bounce because the court's friction grabs the bottom of the ball and throws it on, while slice skids through low. At touchdown, friction takes horizontal speed and restitution returns part of the vertical speed. So read the spin in the air and set your racquet for the height the ball will reach, not the height it arrives at.How to hit a modern topspin forehandTo hit a modern forehand, turn early, meet the ball about a racquet-length in front of your front foot, and swing up as much as forward. Contact has to happen out front, where the racquet head is still accelerating. The topspin isn't a wrist trick. It comes from a path that arrives at the ball travelling upward.How to hit a one-handed backhand, and handle the high ballTo hit a one-handed backhand, turn deeper than on your forehand and meet the ball a stride in front of your front foot, with a straight arm and a closed chest. Pull your off arm back as the hitting arm extends. Its weakness is the ball above the shoulder, so decide before the bounce: take it on the rise, or slice.How to hit a two-handed backhand: which hand does the workHit a two-handed backhand like a forehand with your other hand. Take both hands back together, turn your body, and let the top hand drive through the ball while the bottom hand braces. The two arms form a triangle, so the face isn't pushed back on a high ball, and the short takeback suits the return. About 92 of the ATP top 100 hit with two hands.How to hit a backhand slice in tennisTo hit a backhand slice, use a continental grip, start with the racquet head above your hand and the face open, and swing high to low and forward, carrying the ball toward the target. Don't chop down. Backspin makes the ball hang in the air and land deep, then skid low after the bounce, so your opponent has to hit up.When to go for a winner in tennisGo for the winner only when the reply lands short, inside the service line, or comes slow enough to step in on. Until then, hit the rally ball: high over the net, deep and mostly cross-court, to build the opening. The put-away is a different shot: flatter, earlier and aimed at open court, two metres inside the line.How to hit a volley in tennis: punch, don't swingTo hit a volley, catch the ball on the strings in front of you with a continental grip, keep the racquet ahead of your front shoulder, and step across into the ball. Don't swing. Depth at the net comes from your body moving forward plus the pace the other player gave you, not from your arm. A slightly open face adds a little steadying backspin.How to hit a half-volley in tennisTo hit a half-volley, get low before the bounce, block the ball just after it lands with a slightly open face, and keep moving forward. The lift comes from the face angle and your forward step, not from the wrist. It's mostly a posture decision: stand tall and the face closes on its own, and the ball goes into the net.How to hit an overhead smash in tennisTo hit an overhead, turn sideways the moment you see the lob, point your off hand at the ball, and cross-step or shuffle back rather than backpedalling. Get under it with the ball slightly in front of your hitting shoulder, then hit a shorter, controlled version of your serve. Backpedalling is the single biggest cause of a missed smash.How to hit an approach shot in tennisHit your approach shot deep and low rather than hard, then split step at the service line as your opponent strikes. Depth pushes them back and takes away their angles. A low, skidding slice makes them hit up, so the ball reaches you above the net. Then recover to the middle of the passing angles you left open.How to hit a drop shot and a lob with disguiseTo hit a drop shot that works, set up exactly as you would for a drive or slice, then soften the hand and open the face only in the last instant before contact. Backspin kills the ball's forward momentum so it lands short and bounces low and back. The lob uses the same setup aimed the other way, so the opponent must cover both.
02 Serve and return
How to serve in tennis: the service motion step by stepA good tennis serve is a throw that starts in your legs, passes through your trunk and shoulder, and reaches the racquet last. Legs and trunk supply about 51–55 % of the serve's kinetic energy, and shoulder internal rotation about 40 % of racquet-head speed. Load the knees, let the racquet drop edge-on, reach up to a straight-arm contact and land inside the baseline.How to toss the ball for a tennis serveToss from a straight, locked arm, release at eye level, and send the ball to the same spot every time. For a right-hander, the flat serve's toss sits slightly in front and to the right, slice further right, kick further over the head. The toss sets contact height, spin and placement before you swing, so fix a wobbly serve at the hand first.How to hit flat, slice and kick servesYou hit flat, slice and kick serves from the same motion by changing where the strings brush the ball. Flat goes through it from 6 to 12 on a clock face, slice brushes around the outside, and kick brushes up and across from 7 to 1. The kick is mostly sidespin, and it isn't a slow serve. It's a different bounce.How to disguise your serve and hit the T, body and wideTo disguise your serve, hit the T, the body and wide from the same toss and the same motion. Skilled returners read the toss and the racquet face to predict direction about 300 ms before contact, so any change there is a tell. Disguise isn't a trick motion. It's sameness, so the returner learns nothing before the ball is struck.How to hit a reliable second serve under pressureHit your second serve with the same swing as your first, more brush and one proven target. Slowing the arm to be safe removes the spin that gives you net clearance, so you get a slower ball with less clearance and a returner stepping in. Top-50 men win about 57.5 % of second-serve points, against 73.6 % behind a first.How to return a fast serve: split, read, commitTo return a fast serve, read the toss and racquet before the ball is struck, start your split as the server hits and land it just after. A 200 km/h serve gives you about 333 ms and simple reaction takes about 200 ms, so you can't just react. On court, experts land about 133 ms after contact and move about 177 ms after it.How to return a fast serve in tennisTo return a fast serve, block it: take almost no backswing, set the racquet face early and in front, and punch the ball deep through the middle using the server's pace. A 200 km/h serve gives you about 333 ms, less than a full backswing takes. Against a second serve there's time, so step in and swing fully.Where to stand to return serve in tennisStand back to return a big first serve and step in on a weak second. There's no neutral spot. Every metre back buys flight time but gives the server more angle, and every metre in takes time from the server but demands cleaner timing. Choose the trade before the toss, and change it the moment the first serve misses.How to return serve early and rush the serverReturn deep first, and early when you can. A deep return pushes the server back, and an early one arrives before they've recovered from landing, so the serve and forehand they planned tends to turn into a neutral rally. On a kick second serve to your backhand, take it on the rise below the shoulder and hit deep and central, not at the lines.
03 Move and react
How to read the serve and return fasterTo read a serve, watch the server's body, not the ball, in the last third of a second before contact. The toss, the shoulders and trunk, and the racquet face give the direction away. Call the side, land your split step as they strike, and let the first part of the ball's flight fix your swing timing. Good returners aren't faster. They decide earlier.What is a split step in tennis, and when to do itA split step is a small hop you make before every ball, timed so you land around the moment your opponent hits. Start it on their forward swing. The landing pre-stretches your leg muscles like a spring, so you push off harder toward the ball. Land too early and the spring goes slack. Land too late and you're still in the air.How to get a faster first step in tennisTo get a faster first step in tennis, let your body fall toward the ball, then drive your outside foot into the ground so your first contact points at the ball. The common club start adds a small step away from the ball first, the false step. It feels like getting set, but it's a delay with a foot movement attached.Where to recover after your shot in tennisAfter you hit, recover to the line that splits your opponent's widest possible replies, not to the centre mark. That bisector moves with where they hit from: it matches the centre mark only when they are in the middle. After a sharp cross-court, it sits toward the side you hit from, so you can reach both of their widest replies.Open vs closed stance forehand: when to use eachHit open stance when the ball is late and wide and you have little time, and step in with a neutral or square stance when it's slow and short. The swing barely changes between them. What open stance buys is the next ball: you're already facing the net at contact, so your first recovery step comes sooner.
04 Play the point
When to hit cross-court or down the line in tennisHit cross-court as your default and go down the line only when the court opens: the ball is short, you're inside the baseline and your opponent is wide. Cross-court crosses the net where it's lower, travels into a longer court, and brings the reply back to your side. Down the line reverses all three.What is percentage tennis and how do you play itPercentage tennis means choosing targets and shots so the point ends on your opponent's error more often than on yours. It isn't pushing. It's aggressive with margin: aim through the net window, land past the service line, and go to the bigger half of the court and the weaker wing. About two in three points end on an error.What is serve plus one in tennis, and how to use itServe plus one means planning your serve and the next shot as one play. On the deuce side, serve wide to pull the returner past the sideline, then hit your forehand into the open court. The serve is the only shot you fully control, so use it to make the reply predictable. Decide the plus one before you toss.How to build a point in tennisTo build a point, play it in three acts: open with a ball that makes them move, build by keeping them moving while you read the reply, and finish only when the reply is short, high or hit from off the bisector. Most amateurs only play the finish, from everywhere. The reading is the skill. The finish is the easy part.How to break your opponent's rhythm in tennisTo break an opponent's rhythm, change one thing about the ball they receive: its height, its pace or its spin. A clean striker wins by hitting the same ball from the same height at the same time. A high, heavy ball, a pace-off or a low slice takes that away. Try height first, then pace, then spin, one at a time.How clay, grass and hard courts change your gameClay, grass and hard courts play differently because of two things at the bounce: friction, which takes forward speed, and restitution, which sets bounce height. Clay grips the ball and kicks it up, so points run longer. Grass is slick, so the ball skids low and rewards the serve and first strike. Hard courts sit between, tuned by the sand in the coating.How to play tennis in wind, sun, heat and altitudeTo play tennis in the wind, check it before the warm-up and change your margins. Into a headwind, give the ball more net clearance and a full swing, because the wind holds it in. With a tailwind, take pace off and aim shorter. Lobs and kick serves hang longest, so the wind moves them most.How to tell a new tennis ball from a dead oneYou tell a dead tennis ball by its bounce: it comes up lower and deader than a new one. A ball dies twice. First the felt fluffs up, drag rises and it flies slower and shorter. Later the internal pressure leaks and the felt mats, so the bounce drops. When the balls change, your depth and targets change with them.Where to stand in doubles: standard, I and AustralianIn doubles, pick the serving formation that takes away the returner's favourite shot. The default is standard: the server about halfway between the centre mark and the doubles sideline, the partner at the net guarding the alley. If the cross-court return is hurting you, go Australian to remove it. The I-formation makes the returner guess which way you'll move.When to poach in doubles tennisPoach in doubles when the returner starts their forward swing, not before, or they'll redirect the ball down the alley you just left. You can't wait for contact, because reaction is too slow. Poach more when you're ahead in the game and behind a T serve. Mix in the pinch and the fake so the threat stays real.Where to serve in doubles to set up your partnerIn doubles, serve to set up your partner's volley, not to hit an ace. T and body serves shrink the return angle and feed the poach. Wide opens the court but invites a sharper cross-court reply. Agree the serve target, your partner's move, the expected return and the planned next shot before the toss, as one plan.How to communicate with your doubles partnerIn doubles, decide before the ball is hit. The net player sets the play with a hand signal behind the back before each serve. The pair agrees in advance who owns the middle ball, by position and handedness. In the rally you use four words, mine, yours, switch and back, and you call the switch before a lob lands.
05 Mind
What to do between points in tennisBetween points, run the same short routine every time and end it with one thought about the target, not your body. Pros use about 18 to 20 seconds of the 25 the rules allow. Release the last point, breathe, decide your plan in target words, then run the same ritual into the toss. Don't just tell yourself to calm down.How to play big points in tennisPlay big points by taking less risk, not more. The score tells you which points matter: break points, set points, tiebreak points and 15–30. On those, serve to the body or a proven target, hit into the bigger part of the court and run a pattern you've rehearsed. By one estimate, an average tour break point swings match-win probability by about ten percentage points.Is momentum real in tennis, and how to stop losing streaksMomentum in tennis is hard to prove: many streaks look the same as runs generated at random from each player's serve-win rate. That doesn't make momentum fake, it makes your eye a poor instrument for it. After a slide, the next point is close to independent, so don't change everything. Run your full reset and change one thing you can name.Why you choke in tennis and how to fix itYou choke in tennis by one of two opposite routes: you think too hard about a stroke that should run on its own, or worry crowds out the attention a task needs. The fix for one can make the other worse. Your routine is the one tool that counters both, so pair it with a target you name aloud. That's why "just relax" is a coin flip.
06 Train
How to train tennis fitness: intervals, not long runsTrain tennis fitness with short intervals, about 10 seconds of work and 20 to 30 seconds of rest, not long steady runs. A point lasts 5 to 10 seconds and the rest between points 18 to 20. The phosphagen system fires the point, and your aerobic base refills it in the gap, so your last game looks like your first.How to get faster on the tennis courtTo get faster on a tennis court, train the stop and the read, not the sprint. A point is a few short bursts that each end in a brake. Planned cone drills and reactive agility share less than half their variance, so drills where a partner calls the direction after your first step transfer to the court better than ladders.Which gym training makes your tennis serve fasterThe gym work that makes your serve faster is a mixed programme: heavy lifts to raise your strength, plus rotational throws and jumps that teach you to use it fast. In a 2024 meta-analysis, multimodal programmes raised serve speed most and core-only work didn't reach significance. A serve's acceleration lasts under a quarter of a second, so strength has to be expressed quickly.How to warm up for tennis and recover between matchesWarm up with 12 to 20 minutes of movement, not static stretching: raise your temperature, activate the muscles you'll load, mobilize the joints, then potentiate with sprints and ramped serves. Long static holds before play can briefly cut power. For recovery, sleep comes first, then food and sodium-containing fluids. Ice baths and compression sit lower on the evidence ladder.How do tennis pros practice, and what can you copyTennis pros practice in blocks with a purpose: activation, drilling to a target, live patterns, serves as a separate block, then a cool-down. The part you can copy is the week, not the strokes. Give the serve its own block, end some sessions with a tired, scored game, and cut volume but keep intensity before a match.How to practise tennis so it holds up in matchesPractise with a target, a constraint and a scrambled order, then retest cold at the next session. Blocked practice, the same ball over and over, looks better on the day but loses on retention tests. Random practice, where the shot changes each ball, looks worse today and holds up better later. Fade the feedback and cue the target, not your body.Which tennis drills actually work in matchesA tennis drill transfers to matches when it keeps what a match has: it starts from a read, includes the recovery and carries a consequence. A fed ball to a standing player removes all of that and trains a swing that collapses when someone hits back. Audit your drills with those three questions and add the missing constraint.How to plan a one-hour tennis practice sessionA good one-hour tennis session has a skeleton: an eight-minute ramp, one technical block with one cue and one constraint, live-ball transfer, and a scored close played tired. Pick one priority before you start. Then write down three numbers before you leave, such as first serves to a target, depth hits and unforced errors, so next week has something to beat.
07 Know the game
How tennis scoring worksTennis scoring is "win by two" nested four deep. A game is four points, called 15, 30, 40 and game, won by two clear points. A set is six games won by two, with a tiebreak at 6-6. A match is usually best of three sets, or best of five in men's singles at the Grand Slams.How a tennis tiebreak works, and who serves whenA tennis tiebreak is played at 6–6 and won by the first player to 7 points with a two-point lead. One player serves the first point, then serve alternates every two points, 1-2-2-2, and players change ends every six points. A match tiebreak works the same way but goes to 10. Since 2022, all four Slams use it at 6–6 in the final set.Tennis rules explained: let, fault, foot fault and hindranceYes. A serve that clips the net cord and still lands in the correct box is a let, and the serve is replayed with no penalty. If it clips the net and lands out, it's a fault. Without an umpire, The Code applies: call only your own side, give your opponent the benefit of the doubt, and announce the score before each serve.Tennis court dimensions and what each line meansA tennis court is 23.77 m long, 8.23 m wide for singles and 10.97 m wide for doubles. The net is 0.914 m high at the centre strap and 1.07 m at the posts. Every line enforces a rule, and the shape of the court makes cross-court the safer rally shot: more court to land in, lower net to clear.Which tennis stats actually predict who winsThe tennis stats that track the result are the quiet ones: second-serve points won, what happens by the fourth shot, and the few points with real leverage, like break points. Aces, winners and errors describe the last shot, not why the match was won. About two points in three end within four shots, and the box score never tells you that.How does Hawk-Eye work in tennis, and how accurate is itHawk-Eye works by filming the ball with about ten high-speed cameras, crossing their sight lines to fix its position frame by frame, and fitting a flight path through those points. The bounce mark is computed from that path, not photographed. Its claimed mean error is about 3.6 mm, inside the 5 mm tolerance the ITF requires.How to judge a good shot in tennisA good tennis shot is judged by the ball itself, not by what happened next: how deep it lands, how low it crosses the net and how fast it travels. Depth and speed steal your opponent's time, angle steals their position. Rate depth first, net clearance second and speed last, because speed is the input the eye overrates.What makes a big point in tennis: win probability and leverageTennis win probability is each player's live chance of winning the match, computed from the score and how often each wins points on serve. Leverage is how much one point moves that chance, and it's what makes a big point. A 30–40 break point at 5–6 in a deciding set carries huge leverage. 40–0 at 3–0 carries almost none.What is Elo in tennis, and why it beats the rankingsElo in tennis is a rating that predicts who would win a match, updated after every result. The ATP and WTA rankings reward results over 52 weeks, with bonuses by round and tournament, so they measure what you entered and won. Elo measures strength. On the 2019 Davis Cup finals, Elo called 72 % of matches right and the ATP ranking 60 %.How long are tennis rallies, and what to practiseMost tennis points are short: about two points in three end within four shots, and more than 70 % on grass, and the most common rally length is one shot. By surface the share runs from 65% to 77%. That means the serve, the return and the next ball decide most points, so they're worth a bigger share of your practice time.What made Federer, Nadal and Djokovic so goodFederer, Nadal and Djokovic shared one engine, the chain from hips to trunk to arm, and built three different answers on it. Federer took the ball early and stole time. Nadal hit a heavily spun left-handed forehand that landed high on a right-hander's backhand. Djokovic returned early and deep, turning the server's weapon into a neutral rally.Who are the greatest women tennis players of all timeChris Evert, Martina Navratilova, Steffi Graf and Serena Williams each set the standard of their era, and each added one mechanism to the game. Evert brought depth without error, Navratilova the net and conditioning, Graf the run-around forehand, Serena the serve. Serena holds the Open Era record of 23 majors. Graf's 1988 Golden Slam has never been matched.What Alcaraz, Sinner and Świątek changed in tennisAlcaraz, Sinner and Świątek each added something to tennis rather than imitating the Big Three. Alcaraz made variety a weapon, above all a disguised drop shot. Sinner took time away with flat, early contact off both wings. Świątek brought the heavy forehand to the women's game and took it off clay. Every count about them moves, so date it.How to read a tennis head-to-head rivalryRead a tennis rivalry by splitting the head-to-head by surface first and by year second, then finding on film what one player changed to solve the other. Evert and Navratilova played 80 times. Navratilova led 43–37 overall, but Evert led 11–3 on clay and Navratilova led 10–5 on grass. The overall count hides the story.What are the styles of play in tennisThere are only a few ways to win a tennis match: counterpuncher, aggressive baseliner, serve-and-volleyer and all-court player, with the first-striker as a fifth. Each style is a bet about where points come from, and each pays a known tax for its edge. Surface moves the odds, because it changes how long points last.What great tennis coaches actually changeGreat tennis coaches solve one specific problem, and the way to judge them is to name it. There are two archetypes: the lifelong builder, like Toni Nadal, who shapes technique and values for years, and the champion-mentor, like Ivan Lendl, hired when the strokes are finished and one thing is missing. Majors won during a coach's tenure are an association, not proof of cause.What are the main tennis coaching philosophiesMost tennis coaching falls into four schools: character-first, the technique factory, the tactician and the player-led school. Each one optimizes one thing and fails in a predictable way. The research settles practice design, not coaching style. Random, game-like practice looks worse on the day but is retained better, and faded feedback builds your own error detection.Where tennis stats come from and when to trust themTennis stats come from a pipeline: tracking cameras like Hawk-Eye measure the ball, analysts turn the measurements into metrics, and open datasets let others check the work. To trust a stat, find its instrument, its denominator and the person or institution behind it. If you can't find all three, the number is a claim, not a measurement.What is the Open Era in tennis, and why does 1968 matter?The Open Era is tennis since 1968, when the majors first let professionals and amateurs play in the same draws. Before it, the best players were barred from the majors for taking money. That's why records carry a start date: Margaret Court has 24 majors across both eras, and Serena Williams holds the Open Era women's record with 23.How tennis racquets and strings changed the gameRacquets changed what players could forgive, and strings changed what they could swing. Bigger heads, up from about 65 square inches on wood, bought forgiveness on off-centre hits. The decisive change was polyester string: Gustavo Kuerten won Roland Garros with it in 1997, and the dipping, heavily spun passes it allowed helped make the net a losing position.What makes each of the four Grand Slams differentThe four Grand Slams differ mainly in surface, which changes the bounce and the kind of player who wins. Roland Garros is clay, slow and high, favouring heavy topspin. Wimbledon is grass, fast and low, rewarding the serve and first strike. The Australian and US Opens are hard courts in between. Formats and traditions add the rest.When did the tennis majors start paying women equallyThe US Open was the first major to pay men and women equally, in 1973. The Australian Open followed in 2001, the French Open in 2006 or 2007, depending on the count, and Wimbledon in 2007, a 34-year gap inside one sport. The women's tour wasn't granted. It was built by nine players on one-dollar contracts and settled major by major.