In context, this particular quote seems to be talking more about large-scale battles than individual duels. So, if you've already launched your cavalry at the enemy twice, and they were driven off in disarray each time, then another try is probably not going to work even if your enemy doesn't expect it.
I didn't see any discussion of strategy or leadership in the Book of the Five Rings.
I have, however, seen many cases in competitive gaming where correctly judging what my opponent was expecting me to do allowed me to counter them more effectively. There are a large number of meta-levels there, and operating two levels above your opponent is typically as bad as operating one level below them.
Once again, here's the new thread for posting quotes, with the usual rules:
Please post all quotes separately, so that they can be voted up/down separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)