Why Strings Matter More Than Your Racket

Here's a fact that surprises most recreational players: changing your string setup produces a bigger performance difference than changing your racket frame. Tennis Warehouse University (TWU), the most comprehensive string testing database in tennis, has tested over 500 string setups and consistently shows that string type affects power, spin, comfort, and control more than a $100 frame upgrade.

Former ATP player and coach Patrick Mouratoglou (coach to Serena Williams and current coach of Holger Rune) calls strings "the engine of the racket." The USRSA (United States Racquet Stringers Association) publishes detailed testing data confirming that string choice affects power output by up to 15% and spin potential by up to 25% compared to the same frame with different strings.

The Four String Families

Polyester ("Poly") — The Spin Machine

What it is: A single, solid strand of polyester material. Co-polyesters are polyester blended with other materials for modified performance.

Playing characteristics:

• Spin: ⭐⭐⭐⭐⭐ — The rough surface and low friction between strings allows the main strings to "snap back" on contact, generating massive topspin
• Power: ⭐⭐ — Low powered. Dead, muted response. You generate power with your swing, not the string.
• Comfort: ⭐⭐ — Harsh. Transmits vibration to the arm. Can cause or worsen tennis elbow (lateral epicondylitis)
• Durability: ⭐⭐⭐⭐⭐ — Extremely durable. Lasts 2-4x longer than other string types before breaking
• Tension maintenance: ⭐⭐ — Poly strings lose tension faster than any other type. They go "dead" (lose elasticity and spin potential) long before they break.

Best for: NTRP 4.0+ players with full, fast swings who generate their own power and want maximum spin control. This is what 95%+ of the ATP and WTA tour uses.

NOT good for: Beginners, players with arm issues, players with shorter/slower swings who need help generating power.

Synthetic Gut — The Reliable All-Rounder

What it is: A solid nylon core surrounded by one or more outer wraps. The most commonly pre-strung string in new rackets.

Playing characteristics:

• Spin: ⭐⭐⭐ — Decent but not exceptional
• Power: ⭐⭐⭐⭐ — Good power, lively response
• Comfort: ⭐⭐⭐ — Middle of the road. Better than poly, worse than multifilament
• Durability: ⭐⭐⭐ — Average. Breaks faster than poly, lasts longer than gut/multi
• Tension maintenance: ⭐⭐⭐⭐ — Holds tension well

Best for: Beginners to intermediate players, budget-conscious players, anyone who wants a no-fuss all-around string.

Multifilament — The Arm-Saver

What it is: Hundreds or thousands of tiny filaments woven together, mimicking the structure of natural gut at a lower price. Materials include nylon, polyurethane, PU, and proprietary blends.

Playing characteristics:

• Spin: ⭐⭐⭐ — Moderate. Better than synthetic gut, less than poly
• Power: ⭐⭐⭐⭐⭐ — Excellent power. The string's elasticity adds energy to the ball
• Comfort: ⭐⭐⭐⭐⭐ — The most comfortable synthetic string. Absorbs vibration, arm-friendly
• Durability: ⭐⭐ — Breaks relatively quickly, especially for heavy topspin hitters
• Tension maintenance: ⭐⭐⭐ — Good. Better than poly, slightly less than synthetic gut

Best for: Players with arm issues (tennis elbow, wrist pain), NTRP 2.5-4.0 players who want power and comfort, older players.

Natural Gut — The Gold Standard

What it is: Actual animal intestine (typically cow serosa), processed and treated. The original tennis string and still the performance benchmark for feel and power.

Playing characteristics:

• Spin: ⭐⭐⭐ — Good (not poly-level)
• Power: ⭐⭐⭐⭐⭐ — The most powerful string type. Maximum energy return
• Comfort: ⭐⭐⭐⭐⭐ — Unmatched feel and arm-friendliness
• Durability: ⭐⭐ — Breaks faster than poly, affected by moisture (use a sealant)
• Tension maintenance: ⭐⭐⭐⭐⭐ — Best tension maintenance of any string type

Best for: Serious players who prioritize feel and are willing to pay for it. Excellent for players with arm issues who still want high performance. Popular in hybrid setups (gut mains with poly crosses).

Hybrid Stringing: The Best of Both Worlds

A hybrid setup uses one string type in the mains (vertical) and a different type in the crosses (horizontal). This is the most popular setup on the professional tour and increasingly among club players.

The most common hybrid: Poly mains + gut or multi crosses. You get poly's spin and durability in the mains (where strings move most) with gut/multi's comfort and power in the crosses.

Roger Federer famously played Babolat VS Touch gut mains with Luxilon ALU Power Rough poly crosses. Novak Djokovic uses a similar poly/natural gut hybrid.

String Tension: The Other Half of the Equation

String tension is measured in pounds (lbs). Most rackets have a recommended tension range (e.g., 50-60 lbs). The relationship between tension and performance is counterintuitive:

Start in the middle of your racket's recommended range and adjust from there. Most recreational players benefit from stringing 2-3 lbs BELOW the midpoint.

When to Restring

The classic rule from the USRSA: "Restring as many times per year as you play per week." Play 3 times a week? Restring 3 times a year minimum. Play daily? Restring monthly.

For poly strings specifically: they go dead (lose spin potential and elasticity) after approximately 10-20 hours of play, even if they haven't broken. If your poly strings feel "mushy" or you're losing spin, they're dead — don't wait for them to break.

Common Mistakes

Quick Decision Guide

Sources & Further Reading

1. Tennis Warehouse University. "String Database and Testing." twu.tennis-warehouse.com — Over 500 strings tested with standardized methodology.
2. USRSA (United States Racquet Stringers Association). "String Properties and Performance." racquettech.com
3. Mouratoglou, P. "Equipment Choices at the Professional Level." mouratoglou.com, 2024.
4. Tennis Magazine. "String Buyer's Guide 2025." tennis.com
5. Perfect Tennis (Jonathan). "Complete String Buying Guide." perfect-tennis.com, 2024.
6. Cross, R. & Lindsey, C. Technical Tennis: Racquets, Strings, Balls, Courts, Spin, and Bounce. Racquet Tech Publishing, 2005.