Switchback
A switchback is a situation in which a ladder moves back two or more rows and changes direction. The attacker is still in control after the switchback. Although it is not always a ladder escape, it often can be and is usually a strong play.
For example, consider the following situation. Assume the piece on d1 is in some way connected to the top.
Red makes a switchback as follows:
Now the ladder continues from right to the left on the 4th row:
Note here how Red was able to connect back to the d1 piece. This is not always possible, but even if it isn't, the switchback can be used to create a long line connected to the edge and several rows back from it, a distinct advantage.
A3 Switchback
A single piece at a3 (or at the equivalent cell on the opposite site of the board) escapes 2nd row ladders. It can also be used as a 3rd-to-5th row switchback:
Note that at no point in the 3rd row ladder, Blue could have yielded, because Red's piece could have escaped the resulting 2nd row ladder outright.
For an example, see also A3 escape trick.
A4 Switchback
We have already seen in the first example above that a single Red piece at a4 (or the equivalent cell on the opposite side of the board) can be used as a 2nd-to-4th row switchback. It also works as a 3rd-to-5th row switchback, as follows:
Red's piece 7 is connected to the bottom. Play continues:
Note that if Blue had instead decided to yield the ladder to the second row at any point, the outcome for Blue would have been worse: in that case, Red can perform a 2nd-to-4th row switchback which reconnects to Red's 3rd row ladder.