In my Filipino martial arts class, we practice a variety of striking patterns and a series of blocks against general attacks, usually with sticks but can be translated to empty hand or knife. We drill in these patterns and all their permutations; when we do a High Low High attack sequence, we also practice Low High Low, High High Low, High Low Low, etc. The idea behind this is it allows us to be prepared for any series of attacks, or at the very least, drill it enough so it becomes ingrained in our brains. The hard part is the real version of the drill; the person gives you random attacks in any order and you have to forget all the pre-prescribed patterns and just trust your muscle memory to block each strike.
This takes a little while to get used to, and it really messes with some people when they aren’t able to tell where the next attack is coming from. In reality though, we’re not going to know what an attacker’s next move is, so this is very beneficial training. It’s similar to free sparring, but it’s still very controlled (stick-smashing fingers and knuckles isn’t always fun). Essentially, in the drill, you more or less are re-training your reflexes to immediately respond to any attack with a strong block. That’s one of the reasons the art consists of multitudes of patterns that we practice so often; it’s hammering in the techniques in your brain but also in your body.
A lot of the time, your body will respond quicker than your brain…the more you have to think about the skill the slower it will be! So the goal is to ingrain your defenses into your muscle memory, so you can have more realistic practice with random attacks, and ultimately know how to keep safe.