16x19 vs 18x20 String Pattern: Spin vs Control Explained

When buying a performance racket, you will often see the same model offered in two different string patterns: 16x19 and 18x20. Hitting with a 16x19 vs 18x20 string pattern highlights how string bed density completely alters the playability of the frame.

The first number refers to the vertical main strings, and the second refers to the horizontal cross strings. A 16x19 pattern is considered "open," while an 18x20 pattern is considered "dense" or "closed."

While a difference of two mains and one cross string sounds minor, it completely transforms the playability of the frame. It changes how the racket bends, how high the ball flies off the strings, how much spin you can generate, and even how long your strings last before snapping.

To demonstrate how string pattern density affects performance under uniform conditions, I spent 10 hours playtesting the Wilson Blade 98 v9 in both the 16x19 and 18x20 configurations. Both frames were strung with Solinco Hyper-G at 50 lbs. In this guide, I will break down the science of string bed dynamics.

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1. String Bed Dynamics: Open vs. Closed Density

To understand the difference, we must look at how strings behave when they collide with a tennis ball.

During my playtesting sessions, I made several key observations:

• With the 16x19 pattern, the ball feels like it sinks deep into the string bed, creating a high launch angle.
• With the 18x20 pattern, the string bed feels firm and highly predictable; the ball exits the strings quickly.
• The 16x19 pattern showed string notch wear after just 6 hours of heavy topspin hitting.

The Open Pattern (16x19)

With fewer strings crossing the hoop, the gaps (or "squares") in the string bed are larger. This has two immediate effects:

1. More String Movement: When you strike the ball, the main strings can slide laterally. When you swing up, they snap back into place, acting like a slingshot that grabs the ball and generates heavy topspin.
2. Higher Flex: On impact, the string bed deflects deeper. This pockets the ball longer and cushions the blow, providing a softer, more comfortable feel.

The Closed Pattern (18x20)

With more strings packed into the same area, the gaps are smaller, resulting in a firm string bed.

1. Less String Movement: The strings are locked in place. There is very little lateral sliding or snapback, which reduces spin potential.
2. Lower Launch Angle: Because the string bed is rigid, it behaves like a board. The ball does not sink in, resulting in a flat, linear trajectory. The benefit is directional control—where you point the racket face is exactly where the ball goes.

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2. The Physics of Launch Angle and Dwell Time

To understand the performance differences, we must look at the physics of the ball-string collision:

Dwell Time (Ball-on-String Contact)

The ball remains on the string bed for roughly 4 to 5 milliseconds. During this split second:

• In an open 16x19 pattern, the strings flex deeply, increasing the contact surface area and dwell time. This gives the player a "connected" feel, as they can feel the ball pocketing on the strings.
• In a dense 18x20 pattern, the stiff string bed acts like a solid wall. The ball rebounds quickly with less dwell time, yielding a crisp, immediate response.

Launch Angle (Trajectory Departure)

The launch angle represents the angle at which the ball exits the string bed relative to the racket face:

• A 16x19 pattern has a higher launch angle (typically 2 to 3 degrees higher than 18x20). The string bed stretches and rebounds, launching the ball high over the net.
• An 18x20 pattern has a lower, linear launch angle. The ball leaves the strings flat, allowing players to drive the ball low over the net with complete precision.

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3. Stringing Strategy: Adjusting Tension and Gauge by Pattern

You cannot string a 16x19 and an 18x20 racket identical and expect them to play similarly. You must adjust your setup based on the string bed density:

Stringing for a 16x19 Open Pattern

Because a 16x19 string bed is naturally soft and bouncy, you need to string it tighter to prevent the ball from sailing:

• Tension: String 2 to 3 lbs tighter (e.g. 52 to 55 lbs) to tame the launch angle.
• Gauge: Use a thicker string (e.g. 16 gauge / 1.30mm) to increase durability and slow down friction notching.

Stringing for a 18x20 Dense Pattern

Because an 18x20 string bed is naturally stiff and low-powered, you need to open up the sweet spot and add comfort:

• Tension: String 3 to 4 lbs looser (e.g. 46 to 49 lbs) to soften the impact feel.
• Gauge: Use a thinner string (e.g. 17 or 18 gauge / 1.15 to 1.20mm) to increase string flex and ball bite, adding spin potential.

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4. Baseline Play: High Trajectory vs. Linear Precision

Hitting groundstrokes with the Blade 98 16x19 provides easy baseline depth. The open pattern naturally launches the ball high over the net. If you stand behind the baseline and trade heavy topspin rallies, the 16x19 helps you clear the net and drop the ball deep with margin for error.

Hitting with the Blade 98 18x20 is all about driving through the ball. The launch angle is flat and low. When I hit hard, flat forehands, the ball skidded low over the net. I felt complete control over my targets.

However, if your swing slows down, the 18x20 is unforgiving. Without the "trampoline effect" of the 16x19, your shots will land short, giving your opponent an easy opportunity to attack.

On slice backhands, the 18x20 is superior. The dense string bed keeps the slice low and skidding, preventing the ball from floating up. The 16x19 slice requires a more delicate touch to keep the ball low.

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5. Serving: Kick Serves vs. Flat Serves

On serve, the choice of string pattern changes your tactical approach:

• Serving with the 16x19: The open pattern is ideal for kick and slice serves. The string snapback allows you to carve around the ball, creating high-bouncing kick serves that drive your opponent wide.
• Serving with the 18x20: The dense pattern is built for flat serves. The stiff string bed maximizes energy transfer, allowing you to hit flat first serves with high speed and precision.

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6. String Durability and Cost

If you are a frequent string breaker, the string pattern is a major financial factor.

In a 16x19 pattern, the main strings slide back and forth over the crosses on every hit. This constant rubbing creates friction, causing the strings to notch and eventually shear. If you hit with heavy spin, you can easily break polyester strings in 4 to 8 hours.

In an 18x20 pattern, string movement is restricted. Friction is minimized, extending string life. For chronic string breakers, transitioning to an 18x20 pattern can double the lifespan of your strings.

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7. Summary Recommendation: Which Pattern Should You Choose?

• Choose a 16x19 String Pattern if you play an aggressive baseline game with topspin, want easy depth, prefer a softer and more comfortable feel, and do not break strings frequently.
• Choose an 18x20 String Pattern if you hit a flat ball, play an attacking game on the rise, prioritize directional control, and want to extend the life of your strings.