One of the things I need to teach is how best to keep a person at the optimal distance for Aikido as best as possible. You are starting to see this more in MMA fights where you get some good strikers who know enough to be able to keep the good ground fighters away so the striker can fight their fight.
I was just watching UFC 100 yesterday...so that is my perspective for the moment.
Based on what I saw yesterday on the DVD a couple of thoughts on Optimal distance come to mind.
Brock Lesnar and Frank Mir...interesting fight and both these guys are heavy hitters so optimal distance in their strategy placed a high value on being able to land big punches.
Watching GSP and Thiago Alves...not heavy hitters, but GSP definitely fights a different strategy...he keeps distance and then would move in for a takedown....controlling in a much different way than say Lesnar.
Anyway, I think optimal distance is something each individual needs to figure out for themselves based on the conditions also provided by the situation, rules etc. Optimal distance for Knives is obviously different than for fist fights, which is different from sticks when both guys have them, which is different than when one guy has them.
In all cases of study when you are talking about standup grappling or physical confrontation, there are some basic elements that you can key in on.
Distance and Ma ai. As I stated, conditions and weapons will dictate alot of this as will the size and skills of the opponent. You simply need to discuss this and then limit or control the variables and then get students to focus on how these things affect the situation.
They will learn to either be in the fight or out of the fight, but staying in the "zone of danger" is not a good option. Aikido folk tend to like to stay there in my experiences due to the way we typically train in this zone, which is not improper in kata/waza...but most folks don't learn to transition this zone properly in a non-compliant situation and translate waza/kata practice to reality, which usually leads to a bloody nose or something.
Clinch. you simply have to train the clinch. I don't care who you are, what you study, or what your system or philosophy might be on fighitng. Clinching is universal and it must be studied and perfected. I am always amazed that systems will outright simply disregard clinching.
Use of walls and objects. Once clinch skills are understood, driving your opponent into obstacles and also the hazard the pose to you must be factored in.
WRT to "aikido distance", I assume you mean how to you keep someone away or at bay until you can either enter or dis-engage.
Well I go back to the clinch. Once you understand and can work the clinch, I think then combining that with punch, strikes and weapons...using those things as ways to keep your opponent away can be practiced in a competent matter.
Once they hit point of failure here and get overwhelmed, they can move back to the clinch to re-establish dominance/control.
The interesting thing about the clinch is that once you master the basics of it through pummelling drills, you begin to see that it really is about the basic of aikido. Irimi, tenkan and ikkyo as clinching is all about body positioning, uprooting your opponent and controlling th upper cross or spine. Correctly done, the clinch is a very close irimingae.
If you can't tell, I love the clinch.
It is a great training tool which is ONE, very useful in reality. TWO, it provides wonderful feedback in developing body/feel skills that we want in aikido. THREE, it does wonders in teaching people that they are okay being that close to someone and that they can manage a fight and slow things down. In short, it gives them a default coping skill when they go to point of failure. FOUR, it can be trained relatively safely with a low risk for knee or back injury as long as you work it properly and don't allow takedowns before they are ready to do them properly.
From there, you can build back out from the clinch creating the distance we have learned to love in aikido.
Of course there are other ways, but from my experiences this is the fastest way to convey good skills that are not at all at odds with how we train in aikido.
On another note, you don't need to get all that technical either about hand placement etc...save all that for kata/waza practice...this type of practice is "Macro focused" on creating big scale movements. This I think is also important in training in this manner.