The ornamental design for a ballholder, as shown and described.
FIG. 1 is a front perspective view of the ball holder of this invention;
FIG. 2 is a view of the left side of the ball holder of this invention shown in association with a ball illustrated in phantom outline which is not part of this invention;
FIG. 3 is a view of the right side of the ball holder of this invention shown in association with a ball illustrated in phantom outline which is not part of this invention;
FIG. 4 is a front view of the ball holder of this invention shown in association with a ball illustrated in phantom outline which is not part of this invention;
FIG. 5 is a rear view of the ball holder of this invention shown in association with a ball illustrated in phantom outline which is not part of this invention;
FIG. 6 is a top view of the ball holder of this invention; and,
FIG. 7 is a bottom view of the ball holder of this invention.
The evenly spaced broken lines shown in the figures represent portions of the ball holder that form no part of the claimed design and the dot dash broken lines show environment.