Second Serve: The Most Important Shot in Tennis

If I could fix one shot in every adult player I coach, it wouldn’t be the forehand. It wouldn’t be the return. It would be the second serve. The first serve is glamorous. The second serve is decisive. The gap between a club player and a regional-level competitor is bigger on the second serve than on any other stroke in the game, and the same is true at every level above that. The data is unambiguous and most players still don’t take it seriously enough.

What the data says

On the ATP tour, players win roughly 63–68% of points behind their first serve. The gap between the best and the rest on that statistic is real but small — a top-ten server might be at 75%, a mid-tour player at 64%. So the first serve, while powerful, is not where matches are decided in terms of separation between levels.

Second-serve points won is a different story. The tour average sits around 51–53%. Elite second servers (Djokovic, peak Federer, Medvedev on his best days) live above 58%. Below-average tour pros struggle to win 47%. That seven-percentage-point gap between elite and average is bigger than any analogous gap on first-serve points. And below the tour, the gap widens further. At club level, second-serve points won is often below 35% — meaning the server is at a structural disadvantage every time they have to use it.

There’s a second piece of data that drives the point home. Across the open era, the correlation between second-serve points won and overall win percentage in a match is stronger than the correlation between first-serve points won and winning. The numerical reason is straightforward: every player faces second serves more than half the time they’re returning, because no one makes 100% of first serves, and most pros land somewhere between 60–70%. So if your second serve is a liability, it’s a liability that gets exposed 30–40% of the time you’re serving. That’s a lot of points to give up cheaply.

Why the second serve is structurally hard

The second serve carries a psychological tax the first doesn’t. If you miss your first, you have another. If you miss your second, you’ve donated a point. So players are pulled in two directions: hit it safer to avoid the double fault, or hit it bigger to avoid handing the return a free attacking opportunity. Most amateurs pull toward “safer” and end up with what coaches call a “patty-cake” second — slow, flat, predictable, landing in the middle of the box at 70 km/h with no spin. That’s a free unforced error from the returner’s perspective.

The other reason it’s structurally hard is that it’s the only shot in tennis where you’re playing scared by definition. Every other shot, you’re reacting to a ball and committing to a stroke. The second serve requires you to manufacture aggression at the exact moment you have the most to lose. Top pros have one habit in common here: they treat the second serve as its own shot, not as “first serve, but smaller.” This sounds obvious. Most coaches violate it constantly.

Spin is more valuable than speed on a second serve

The mechanics of a good second serve are nearly opposite to a good first. A first serve maximizes forward racquet head speed at a relatively flat contact, with the kinetic chain dumping everything into linear velocity. A second serve maximizes upward and forward brushing speed against the ball, producing topspin or kick that arcs the ball up over the net with a large safety margin and then bends it down into the box. The reason this matters is geometry.

A flat second serve has to fly with very little net clearance — maybe 20–40 cm above the tape — because the ball doesn’t drop. The acceptable height window is tiny. A kick serve clears the net by 80–120 cm and still lands in, because the topspin pulls it down. The same swing speed that produces a 90 km/h flat serve might produce a 140 km/h-equivalent perceived bounce on a heavy kick, because the ball jumps off the court at the returner’s shoulder.

The biomechanical key is the brushing direction at contact. On a kick serve, the racquet path goes low-to-high and slightly left-to-right (for a right-handed player), brushing up the back-right of the ball. This produces topspin with a sidespin component, which makes the ball bounce high and away. The wrist doesn’t snap forward — it pronates through the contact while the racquet path stays brushing upward. That’s the move that most amateurs cannot do without practice, and it is the move that separates a second serve you can win points behind from one you can’t.

The “second-serve mentality”

Beyond mechanics, there’s a mindset. The top second servers commit to the spin. They don’t hedge. They aren’t trying to hit a slightly-spinny version of a first serve. They are hitting a different shot with a different intent.

In practical coaching terms, this means: pick a target before tossing. Pick a spin. Commit to brushing fully. Accept that the ball will look slow to the eye, because it isn’t trying to be fast. It’s trying to be heavy.

The cognitive trick that helps players make this commitment is what I call the “first-serve-second-ball” framing. When a player is about to hit a second serve, I tell them to imagine it as the second serve of their first delivery — meaning, they get to swing freely with a margin, because if they miss they have another chance. They don’t actually have another chance, but the imagined safety releases the swing, and the swing is what produces the spin, and the spin is what saves the point. Counterintuitive, but it works in practice.

What good drilling looks like

Most second-serve drills are wrong. The most common one — “hit ten second serves, count how many go in” — measures the wrong thing. A second serve that goes in at 80 km/h with no spin lands you in trouble. A second serve that misses long because you brushed too steeply teaches you something valuable.

Better drills for a competitive player:

• Target zones. Three boxes inside the service box: middle, body, wide. Hit five second serves into each, scoring spin and depth qualitatively. The point is to develop placement, because a good second serve relies on placement and spin combined.
• Net clearance ladder. Hit second serves with a target net clearance of 60 cm, then 80, then 100. The player has to learn what swing produces what arc. Builds the kinetic intuition.
• Live points starting from a second serve. The most match-realistic drill there is. The server starts at 0-0 in a game, but their first serve is automatically out — every point starts from the second. Forces the player to actually use the shot they have, under pressure, with consequences.

The total weekly second-serve practice budget for a competitive adult should be at least 30 minutes of focused work. Most amateur players I see spend zero minutes a week on this. They hit second serves only when they miss firsts, which is the worst possible way to practice the most important shot in the game.

The case for the kick on every second serve

This is a coaching opinion, but it’s an evidence-informed one. For most players above the beginner level, the answer to “what should my second serve be?” is: a kick serve, hit to the body or backhand, with full commitment. Not a slice. Not a flatter spin variation. A real kick.

The reasons are: the kick gives the largest margin over the net; the topspin pulls it down inside the line at a much higher swing speed; the high bounce takes the returner out of their comfort zone; and the brushing action is similar to the modern topspin forehand, so the motor pattern reinforces other strokes. Slice second serves work for some players, but they tend to sit up on slower surfaces and are easier to attack. A well-hit kick is the percentage shot.

The exception is players who physically cannot generate the racquet speed for a kick — typically beginners and some older recreational players. For them, a heavy slice second serve to the backhand is the right compromise. But for anyone with a competitive ambition, the kick is the shot to build.

One thing to do on court tomorrow

Add 15 minutes of dedicated second-serve practice to your next training session. Pick a target box — body, to the returner’s backhand — and don’t move on until you’ve hit 20 of them with what you think is real spin. Don’t measure success by “in or out.” Measure it by net clearance and bounce height. If the ball is clearing the tape by less than a foot, it’s not a real second serve yet, and the next time you miss your first in a match, you’re going to find out.

About the author: Emre Köse is a tennis coach at Beykoz Tenis Kulübü and GDTennis in Istanbul. He holds a BSc in Physical Education Teaching and Coaching from Marmara University.

Related in this series: Where serve speed actually comes from · Flat, slice, kick: spin mechanics and tactical use · Pronation: the most misunderstood serve element · The return is the second-most-important shot