Affordances are relational, a connection between you and the object you are interacting with - the more you see of them, the more ways you have to interact with it.
In the case of single combat with blades, there is a purpose to the interaction - prevailing against your opponent - so the affordances in this case relate to achieving that end. And the object that you are interacting with is your opponent ... and the weapon they are wielding.
There are many different ways of reaching the goal (i.e. stopping the opponent), a little like paths through the forest. Each has a start point that connects to the next, and so to the goal.
The more paths you see and the more affordances you can grasp, the more ways there are through the forest.
Each path demands certain skills, many overlap, yet each path is slightly different, and along that path, the possible branches depend on your ability to see them.
One path may be - Cut weapon hand, opponent drops weapon, finish.
Another - Threaten opponent's head, bridge created through weapon contact, close, shunt opponent away, cut to finish as they fall back.
Perhaps another - Feign an opening to cause the opponent to rush in, step off line, drop weapon and cut under opponent's strike whilst stepping past and away.
So many ways, so many potential solutions .... and so many moments where the situation can change.
If each moment contains an affordance, each part needs practice both to see it, and to be able to do something useful with it, whether it succeeds or not.
For instance, hand targeting requires accuracy and speed, and the follow up requires the ability to recycle efficiently, bringing the weapon up on target as fast as possible. It also requires a knowledge of range and evasion.
However, should circumstances shift during the hand strike, one might fail to hit the hand, and perhaps connect with the weapon instead. This gives a bridge, and thus the possibility of the shunt back and cut ..... Or if the opponent retracts the hand, now perhaps one can close using only the live hand to control the opponents weapon, and you can just cut on the run by ....
Start from another place and more affordances occur, but appear and connect to each other in different ways. Each part needs skills, and the ability to change paths in mid stride if something does not go as planned.
If the path begins by drawing the opponent to block and creating a bridge, it require the ability to express a strike, in other words to make it look as threatening as possible to elicit a reaction. It also requires good weight shift and footwork to drop into the bridge directly behind the block, and the follow up requires a knowledge of anatomy and structurally strong and weak lines, and the ability to cut a falling target.
If the block you need your opponent to do does not manifest, what of this moment? Can you just follow through with the strike and hit them? Do they back up? Perhaps this affords the opportunity to close anyway? And if they strike at you ... and you block ... is that not the same position that you were looking for originally ... as long as you can gain the initiative?
Feigning an opening requires acting ability, though just missing by accident works well too .... but both require evasion which requires footwork and a knowledge of cut angles, where is dangerous, where is not, and an appreciation for the importance of the exit.
All require a knowledge of range and timing, how a sword works (and all the affordances it gives), how people move, and most importantly, how to not get hit yourself as you pull off the win.
One of the great things about flow training is that you can work on each, separate, piece within the flow - hand tagging, evasion, bridging, whatever, OR you can chain the whole series together to the end game.
The ability to break down the whole into bite sized pieces means that more paths through the forest can be uncovered, and the more often the affordances, or 'nodes of opportunity' if you like, will 'appear' to ultimately join up into a map, all leading to the same destination.
Well .... Such is the plan at least ....