I Tested These 5 Strings Over Months on Court – They’re the Best for Flat Hitters

For the past couple months I have been taking strings to the courts on a regular basis, testing them out for my own game and for the clients that keep asking me the same question, “What’s the best string to flatten out my ball?” It comes up again and again – flat hitters who want control without killing their power, players who hit through the ball and need a stringbed that responds well to a direct swing and juniors who are starting to generate their own pace and want something that doesn’t fight them.

So I’m collating the best options I’ve discovered after months of playtesting. I’ve focused on round, or low-profile, string that gives flat hitters what they really need, which is control, tension stability, and a stringbed that responds well to a direct, penetrating swing. The worst string for a flat hitter is often the one that’s trying to be too aggressive with spin – shaped, grippy strings that lock up and kill your power.

With a few minor exceptions. Some shaped strings can work for flat hitters, if they are more balanced and not too aggressive, but I have focused on what tends to work best: round profiles, low to medium power, and solid feel. Most flat hitters need a string that won’t give them too much free power, but will keep the shots tight and consistent. I think for flat hitters, round, control-oriented polys are usually the best bet.

1. Luxilon 4G Soft 1.25mm

This was one of the first strings I returned to over the last few months of testing. Luxilon 4G Soft is a great option for flat hitters who like control and a little more comfort than the original 4G. It’s a round polyester that doesn’t lose the look and feel of 4G but in a softer, plusher version. It has that medium-soft poly feel which plays very well and a semi-muted profile that doesn’t have too much personality but just gets the job done with no drama. On court I found that it gave flat hitters consistency and tension maintenance without feeling harsh when I’m swinging hard – which is exactly what I recommend to clients who generate their own power and value control. More on Luxilon strings.

Specs:

• Type: Round polyester
• Gauge: 1.25mm / 16L
• Feel: Semi-muted, soft, controlled
• Best for: Flat hitters wanting control with comfort and consistency

2. HighString Zeus 2.0

It feels like a modern poly that is made just for precision which is why Zeus 2.0 is the highest ranked control poly in recent test rankings. On the court I found it to be reliable, crisp and controlled and yet still giving me the confidence to swing out fully. It has a larger “swing window” which makes depth control phenomenal, especially in tighter patterns – which is exactly what flat hitters need when they’re hitting through the ball and want to keep shots tight. I’ve put this in a few clients rackets over the last couple of months and the feedback has been consistent: they can hit hard without the ball flying out and depth control is just better.

Specs:

• Type: Modern control polyester
• Gauge: 1.25mm
• Feel: Crisp, reliable, controlled
• Best for: Flat hitters wanting modern precision with depth control

3. Solinco Confidential

Confidential is a bit of a combination between Tour Bite and Hyper-G with its own twists, and it’s one to try out whether you’re hitting with spin or powering through the court with a flat shot. I have used this string a lot over the last few months and it does a good job holding tension on the lower end, plays more powerful than Tour Bite and slightly less powerful than Hyper-G. The slightly pentagonal shape generates a decent amount of topspin on groundstrokes, but was also explosive enough that I liked to hit through the court on put-away shots. What I tell clients is that the Confidential is a controlled, more comfortable response than the Tour Bite, making it a great middle ground for flat hitters that want some spin versatility without giving up power.

Specs:

• Type: Pentagonal co-polyester
• Gauge: 1.25mm / 16L
• Feel: Controlled, comfortable, balanced
• Best for: Flat hitters wanting control with some spin versatility

4. Genesis Infinite Blue

Genesis Infinite Blue is a lot of fun to use, it does feel firmer but it is also a beautiful string that gives you great spin while still being playable for flat hitters. It feels crisp and has a spin-friendly profile, so it’s a good option for aggressive flat hitters who want some modern character in their game but don’t want to lose precision. I’ve put this in a few rackets for clients who are starting to flatten out their ball more and the response has been good; they like the firmer, crisp feel when they’re hitting through the ball with intention.

Specs:

• Type: Firm co-polyester
• Gauge: 1.23mm
• Feel: Crisp, firm, spin-friendly
• Best for: Aggressive flat hitters wanting crisp feel with some spin

5. Signum Pro Plasma Pure

Plasma Pure is a balanced control poly with a comfort edge. It’s smoother, easier to handle and stays playable after hours of heavy hitting. Even if you’re swinging hard, it doesn’t feel harsh, which makes it a good option for flat hitters looking for control without arm fatigue, as many of its competitors do. I have tested this over a number of sessions and it gives you good speed on first serves and still keeps the ball controlled, and it handles second serves well without dropping short. This is a string that I keep coming back to for clients who are heavy hitters but still want comfort.

Specs:

• Type: Round control polyester
• Gauge: 1.23mm
• Feel: Smooth, balanced, comfortable
• Best for: Flat hitters wanting control with comfort and heavy hitting durability

Other Notables to Consider

If you want to look beyond these five, there are a few other strings that are worth checking out. Grapplesnake Soldier is a high performance polyester for the player who hits big and demands absolute stability throughout the life of the string. It is in the same control family as the Tour Sniper and the Tour M8, with a seven-sided heptagon profile that provides more spin than the Sniper, while keeping the launch angle predictable and controlled. “I’ve been testing Soldier for the last couple of months and it’s a low powered, very stable racquet that’s great for intentional flat hitters that commit to their shots.

Silvester Hepta-Plus is a shaped poly for spin and control with a firmer edge. The heptagonal profile really bites into the ball making topspin and slice easy to generate. Less free depth, but more bite and shape. Firmer, grippier, more spin oriented than Energy 1.23 If you’re hitting through the ball with intention This can work for flat hitters who want some spin without getting too aggressive.

Babolat RPM Blast is a slick-surfaced high-spin polyester. It’s designed to improve snapback and is used by heavy topspin players such as Nadal and Tsitsipas. It’s more spin oriented, but some flat hitters with medium spin love it for the control and low launch angle which translates into better penetration through the court.

Final verdict

After a few months on court testing these strings for myself and for clients, here’s what I’d recommend: 

1. Luxilon 4G Soft for control with comfort and excellent tension maintenance.
2. HighString Zeus 2.0 for modern precision with phenomenal depth control.
3. Solinco Confidential for control with some spin versatility and balanced feel.
4. Genesis Infinite Blue for crisp feel with spin for aggressive flat hitters.
5. Signum Pro Plasma Pure for control with comfort for heavy hitters.