Kirschbaum Pro Line II String Review

Control - Score: 88 / Power - Score: 45

Pro Line II gave our team amazing control, which is exactly what Michelle needs to keep her huge strokes inside the lines. She said, "This string is low powered, and I loved it! I could hit out and not worry about balls flying out. The string had a nice, dead response without feeling mushy, stiff or uncomfortable. I could hit big and was rewarded when stepping up to put balls away. I tend to overhit when I'm tight, so this string's control was good for me."

"This string falls on the control side of the spectrum," said Marco, who settled into some confident ball striking with this co-poly. He added, "I liked how it gave me the confidence to swing at top speed and supply my own power. At 55 lbs it had very solid control, but it also didn't feel dead like some other polyesters I've used that had similar control."

Spin - Score: 68

Pro Line II boasts the kind of low-powered response that is perfect for generating high stroke speed -- a key ingredient of spin. Despite Pro Line II not having edges, dimples or dents, Marco got plenty of grip from this round co-poly. He said, "I found good pocketing and noticed the string grabbing the ball nicely on contact. I found a noticeable increase in spin on my shots with a just slight increase in racquet head speed, which is the kind of response I look for in a string. It was easy to connect with the ball with this string, and I knew where my shots were going to land."

Michelle was less impressed with this string's spin potential. She said, "I can't say I found ample amounts of spin potential in this string, but it was adequate. I don't think spin would be the selling point here. The string did provide decent snapback, and I wouldn't say the spin level was detrimental by any means, it just wasn't the standout feature for me."

Comfort - Score: 63

The stiff construction of poly-based strings is what gives them such outstanding control, making them perfect for advanced players who make their own power. Unfortunately, the high stiffness level often comes with a trade-off in the form of less comfort. According to our team, Pro Line II comes with no such trade-off. Michelle was impressed, saying, "Usually with deader, low powered strings comes an uncomfortable response. I've come to expect a stiff string if I'm getting lower power levels. Luckily, that wasn't the case with Pro Line II. I had no issues with comfort. I strung it in the high 50s without any issues. The string felt softer than other strings that offer the same amount of power. I never noticed any discomfort outside the sweetspot or on mis-hits with this string."

Marco also found this co-poly to be quite comfortable. He said, "For a polyester, this string was comfortable and felt even softer than its stiffness rating suggests. I never felt like I had to compromise my swing to avoid uncomfortable areas of the stringbed. The high control should enable players to lower the tension for even more comfort."

Feel - Score: 80

For our team, the feel of Pro Line II was a standout quality. This string managed to feel firm and precise without ever feeling uncomfortable. It was quite forgiving compared to strings with a similar level of control and durability. Marco was impressed. He said, "Pro Line II played firmer and more controlled than the softest polys on the market, but it also has noticeably more give than the polys I typically use, like Solinco Tour Bite 16 or Luxilon ALU Power 1.38. The overall feel from the stringbed was crisp without transmitting uncomfortable shock on off-center hits. I was very impressed with the combination of control and feel."

For Michelle, this string checked all the right boxes. It was firm without being stiff yet forgiving without being mushy. She explained, "Pro Line II gives the stringbed a comfortably firm feel. Off-center shots definitely feel a little firmer, but they were never uncomfortable. Unlike when I play with the softest co-polys, I never felt like I was losing the ball on the stringbed. I felt very connected to my shots with this string."

Playability Duration - Score: 86

Pro Line II is pre-stretched at the factory. This manufacturing technique is intended to provide superior tension maintenance and playability duration. Michelle wasn't convinced. She said, "I found this string to be pretty average in terms of playability duration. Nothing exceptional, but also nothing exceptionally bad. I was ready to restring after two weeks, especially since it's already a lower powered string."

Marco was more impressed with Pro Line II's longevity than Michelle was. He said, "I didn't notice a significant change in playability over the course of my playtest with this string. It held tension well and its performance held pretty constant; there was little to no string movement too, which was good."

Overall - Score: 85