The Pro Staff 6.0 version was manufactured in four head sizes: 85, 95, 110, and 125 square inches. The 85 is unforgiving for the currently popular semi-western topspin style with its 12.6 ounce (357 g) weight and low power. The 95 is more forgiving of off-center shots with an overall weight of 12.2 ounces (346 g) and a lower swingweight (317 as opposed to the 85's 326). However, it has a higher flexibility, particularly in the upper hoop, due to its larger head size, which has been described as undesirably "whippy". Both have a 16x18 string pattern making the frame more open and easier to generate spin albeit the user must generate much of the spin's power with timing and wrist pronation. The Prostaff 6.0 also performs admirably well with flatter hitters (as evidenced by the success of Pete Sampras, Chris Evert, and Mary Pierce) as a result of its considerable heft and control. A flat hitting power-oriented game will therefore benefit considerably from the inherent control and stability of the frame. The small headsize of the 85 and Perimeter Weighting System also minimize the torque on off-centre hits, further enhancing control at impact.