This is a helpful hint we can share with those who might welcome a little assistance in overcoming the puzzle's challenges. As you start, try to think of each blocking key combinationi as eight separate puzzles, one puzzle for each switching bar, starting with the eighth bar (furthest from the exit block). Focus first on how to switch that eighth bar. To get to it and move it, you must first set the other seven slide bars in exactly the right combination in relation to the blocking key pattern and the exit block to allow the gate to open for the eighth bar. If even one of the first seven bars is switched in the wrong direction, the last bar cannot reach the gate, or the gate cannot be opened to switch this bar.

How should you set up the first seven bars? Focus next on the seventh bar. In its current position, would it be blocked by the blocking key which it would oppose when the eighth bar is in the gate to be switched? If so, it must be switched before the eights bar can be switched.

If switching the seventh bar is necessary to switch the eighth bar, focus next on the sixth bar. Would the sixth bar be blocked by its opposite blocking key when the seventh bar is in the gate? If so, it must be switched to switch the seventh bar to switch the eighth bar. Is the fifth bar in proper position when the sixth would be at the gate? The fourth? and on and on.

The essential concept of the puzzle is to concentrate on solving the switching bars furthest from the main block, even though the puzzle constrains most of your actions to the bars nearest the block. Progress made on the near bars must give way to progress made on the farther bars, because the relationship between switching bars and their opposing blocking keys changes with each puzzle, you have to lose some to win some.

After the eighth bar is switched, of course, you are left with a new switching sequence to solve, which now has seven bars which may or may not have to be switched, instead of eight. The process explained above must be repeated, switching the seventh bar to the open position, and then the sixth, etc., until each of the eight bars have been solved in order.

Fortunately, each succeeding bar is easier than the last, because fewer remaining bars get in the way. When only the second and first bars are left, you are almost out of the woods. Out of the woods that is, until you realize that the process must be reversed to get the carriage back in the base for the next would be puzzlesolver to take his or her turn!

One final suggestion. Although resetting the puzzle can be as challenging as solving it, once the puzzle has been solved it is sometimes handy to readjust all the keys to the "1" position. The bars can then be moved back into starting position in order, and the keys repositioned in any arrangement for the next puzzle sequence.