For years I've had no problem with any particular spare, however, lately I can't seem to make a 10 pin.  I'm using a plastic ball and standing with my left foot on 35 and aiming at the fourth arrow (20 board).  If I feel like I've thrown it good I sometimes miss left.  Other times it goes in the gutter just short of the pin.  I've tried moving out and in with no luck.  I've tried watching the ball go over the mark but that has not helped either.  Am considering putting a little surface on the ball so it will grab some before going in the gutter.

If anyone has had this problem, what did you do to get out of it?  It's really messing up my game.  Left four ringing 10's yesterday and only made one.  Cost me a 600 series.

Would appreciate any help.