With the release of the new Wilson Spin Effect racquets, the Steam 99 S and Steam 105 S, people are talking about the way that spin is produced and what effects a racquet can have on spin production. Wilson utilizes an open 16×15 string pattern that it claims helps to produce noticeably more spin than a traditional 16×18 or 18×20 string pattern. The difference lies in there being fewer cross strings than main strings, thus opening up the stringbed and creating more space in between the strings.
Interestingly enough, our TW University professor, Crawford Lindsey, was onto something very similar a few years ago when he started testing the effects that different string patterns had on spin. He conducted experiments (outlined in his “Spin and String Pattern” article in September of 2010) to test which string patterns were more effective in producing more spin.
For us to understand the TW Professor’s experiment, we need to understand how spin is produced during a shot. During a topspin shot, the ball contacts and slides across the stringbed. Where stringbeds differ in spin production is whether or not the ball also moves and stretches the main strings sideways out of position (since the mains are the strings that are horizontal at the time of impact). If the mains are moved and then snap back quickly into place, they will transfer energy back into the ball that causes it to rotate. This is what produces the extra topspin on your shot compared to stringbeds where the mains do not move and snap back. The more a main string is stretched sideways, the more energy it can then transfer back into the ball and the more spin it produces.
So what are the ways that racquet technology, or more specifically string patterns, can affect how much a main string is stretched? We found that the more unimpeded contact the ball has with the main strings, the more it can move and stretch them. String patterns with fewer cross strings or a larger space between each cross string allow the ball to get this increased access to the main strings. Furthermore, fewer cross strings cause less string-to-string friction, which is the force that prevents the strings from sliding on themselves. With fewer crosses, it’s easier for the main strings to move and stretch sideways.
These two factors allow us to deduce that string patterns with fewer cross strings will produce more topspin. As the TW Professor states in his article,
“The results of these experiments strongly suggest that alterations to one’s string pattern can influence spin. The more open the pattern, especially the cross strings, the more access the ball has to the main strings in order to tangentially stretch them and store and return tangential energy, increasing spin-producing torque and rebounding the ball at a higher angle.”
This is precisely the science behind Wilson’s new Spin Effect technology, which opens up the space between the strings by utilizing fewer cross strings. In turn, the main strings can slide more at impact and create more spin-producing energy while the ball is on the strings. As the ball leaves the strings, the higher launch angle that the Professor discusses is noticeable, along with the increase in topspin that causes the ball to dive down at the court on your opponent’s side of the court.
For more information, here’s a link to our TW Professor’s article regarding his experiments in 2010.
Thanks for reading,