The play of choice is to put the cue ball about where a good side-of-the-rack break ball would be and then play full onto the ball next to the corner ball on that side. This pushes balls both to the foot rail and opposite side rail and often leaves the incoming player in a very bad position.
That safety is generally so reliable that I rarely check for gaps in the rack, but I have been bitten by gappy racks when no ball gets to the cushion. Usually the mistake people make when playing the safe is to hit it too hard so the loose balls come back to the rack.
There is a similar shot when you are below the solid rack (shot B).
For both positions, play softly with follow. You want a nearly full hit, slightly favoring the side that will leave the cue ball frozen to two balls (the one you hit and the striped ball). The follow is to help stick the cue ball to the ball you contact in spite of the cue ball's tendency to bounce back from multiple frozen balls.
For shot A, if the cue ball is to the right of the "limit" line you can't hit the object ball full and the shot is iffy. Shot B is shown near the limit line and you should play off the corresponding ball on the other side of the rack. If for some reason that side is not available and you have to play to the ball shown for B, you can try jacking up with right side and swerve into the needed line. You will have to practice that kind of soft swerve if you want it to work in a game.
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There are two problems with the "roll to the head pair" safety of the OP. The first is that there is often a very easy return safe, either to barely touch a side rail or to go to the side rail and come back with reverse side spin to freeze on the side of the rack. The second is that if there are gaps in the wrong places a ball can pop out and leave your opponent an easy shot.
The third problem that we used to have at the rec center is that if the corner ball moves away, the ball next to it is often dead to the corner on a three-ball combination down the side of the rack if you just blast the cue ball along that line. Maybe there is a double hit or three. We weren't real nitty about clean hits back then. :wink:
The standard play when up-table and to a solid rack is to lag to the back of the rack very softly so that a couple of balls are just loosened out the front of the rack. Nothing gets to a cushion but you avoid any chance of leaving a shot.