Black Knight


"The ultimate poly for high performance players!"

An innovative, high performance string designed for the modern tournament player. The latest 6 sided co-polyester blend ensures and ideal balance of power, control, access to spin and unexpected arm-friendliness. Exceptional durability and tension stability will guarantee the avid player an ultimate, long lasting playing experience.

Who should try the string?

  • Players who are used to playing with co-poly strings
  • Players who are looking for a well balanced string with great directional and depth control, exceptional durability and access to spin.
  • Playing level LK: 9-1, NTRP: 5.0-7.0, college players, ITF players, etc... (advanced - high performance level), UTR 9-16+
  • High level junior players from age 15 and up
  • NOTE: This string plays quite differently at 16g (1.28mm) than at 18g (1.18mm). Although Black Knight is generally recommended for high level players, at 18g this string could also become very suitable for competitive, recreational players who look for an arm-friendly, durable, control oriented string with great access to spin.

  String Characteristics:





Tension Stability

Spin Potential


  String Specifications:

String Name: Black Knight

Gauges: 16g (1.28mm). 17g (1.23mm), 18g (1.18mm)

Length: Sets: 12.2mm/40ft, Reels: 200m/656ft

Color: BLACK

Official Product Reviews:


"35 year old open level tournament player. This string is a perfect fit for my game. Offers just the right amount of power and control. Excellent durability and it also keeps its tension until the string breaks. Will be ordering a reel."


Advanced Players String

"Fantastic string for the price with great bite. A very nice balance of control, power, and durability for advanced players. If you are not an advanced player look elsewhere."

Amazon Customer

Perfectly Balanced

"I always liked the quality of Tier One Sports strings but I think this is their best offering so far! I used to play national junior tournaments and now compete at high level adult tournaments. Control…check, durability….check, tension stability…check, playability….check!"


Who are we?

We are a business specializing in high quality tennis strings. Our mission is to offer those products at affordable prices. We can only do so by running a cost efficient business which includes not paying outrageous marketing expenses to elite tennis players to advertise our strings.  Our growth rather comes from hundreds of positive posts and reviews at accredited tennis forums. We highly value the feedback from those tennis enthusiasts who validate the quality of our products daily.

Why Tier One Sports?

Tennis String Innovation:  

Our production team was able to develop a co-polyester compound that is superior in tension stability and string stiffness to most poly strings in the tennis industry.

Qualitative Lab Test Results Do Matter:

There are 2 fundamental factors that build a foundation for the quality of a co-polyester string: tension stability and string stiffness.  Having tested a great variety of strings from our competitors, we recognized the very limited number of strings on the market that perform well in both areas. Either the string is overly stiff or loses tension too quickly. 

Bob Patterson from the USRSA (United States Racquet Stringers Association) provides their readers with a comprehensive list of tennis string lab test results for string stiffness and tension stability. Bob was kind enough to test all Tier One Sports strings as well.

To offer some insight into the quality of our strings we made sure to compare them to some of the "best", well known strings in the industry!

Tier One Sports Black Knight:

  • Black Knight 1.23mm: String Stiffness: 197 (lbs/in), Tension Stability: 15.39 (lbs)

String Competitors:

  • Babolat RPM Blast 1.26mm: Stiffness: 273 (lbs/in), Tension Loss: 17.13 (lbs)
  • Luxilon Alu Power 1.25mm: Stiffness: 242 (lbs/in), Tension Loss: 17.13 (lbs)
  • Head Lynx Edge 1.25mm: Stiffness: 181 (lbs/in), Tension Loss: 21.59 (lbs)
  • Yonex Poly Tour Spin 1.25mm: Stiffness: 212 (lbs/in), Tension Loss: 15.41(lbs)
  • Tecnifibre Black Code 4 1.22mm: Stiffness: 199 (lbs/in), Tension Loss: 17.42 (lbs)
  • MSV Focus-Hex 1.27mm: Stiffness: 220 (lbs/in), Tension Loss: 16.45 (lbs)
  • Luxilon 4g 1.24mm: Stiffness: 249 (lbs/in), Tension Loss: 13.30 (lbs)