String tensions in the mid-40 pound range are much more common today on the pro tour, for both men and women, than tensions in the mid-60s. This means pros have shed as many as 20 pounds off their tensions over the last decade.
For years, most followed the adage "string loose for power, tight for control." A racquet strung loose with a synthetic or natural gut allowed the ball the stay on the strings longer, giving comfort and punch to your shots, but with the lack of pinpoint control high-level players demand. So high tension was the rule on the pro tours with 65 and even 70 pounds being common, especially with players using gut.
Today, poly strings have changed all that. These slick and stiff strings, strung looser, give high-level players a unique combination of power and control, through added spin.
The issue for players below the 5.0 level comes with the increased number of shots not hit perfectly within the sweet spot, particularly those hit above or below the longitudinal axis of the racquet. This causes the frame to twist during contact, which can lead to large errors in depth and directional control. Low tensions can magnify this problem.
That is where the Pojie comes in. The compression core of Pojie produces greater string deflection—much like a looser string tension—providing added spin and comfort, but without having to drop tension to the point where the racquet rotates on off-center hits.