Wide string pattern
This is the North Star when looking to hit with added topspin. Simply put, more space between the strings lets them move—or stretch—more at contact, and consequently return more energy to the ball. There are exceptions, but most spin-friendly frames on the market today have 16×19 string patterns. This allows you to put more work on the ball, but still maintain a good measure of control.
Keep in mind that not all 16×19 frames are created equally. The new Wilson RF Collection racquets all have 16×19 string patterns, but the spacing is fairly dense in the sweet spot and widens closer to the frame. You can still apply topspin to the ball, but it’s more limited than with other 16×19 frames that have a wider spread in the center of the string bed, such as the Head Extreme.
Read more: Roger Federer unveils groundbreaking RF Collection by Wilson
The grommets in a frame like the Extreme can also play a role. When the holes are a bit bigger, or have elongated shapes, it allows the strings to move more at contact before snapping back into position. This is another asset to adding spin to the ball.
