99.99% attackers in aikido don't know how to deliver a difficult attack. They do so called ‘zombie attack'. It is not worth for me nor to discuss it, nor practice it.
However sometimes we can meet somebody who really knows how to attack. He usually has a background in street fighting or competition oriented sparring and matches.
In such very rare and precious cases it is virtually impossible or most difficult to do any technique, due to lack of clear commitment. Of course such commitment exists, otherwise the effect of attack would be null, but it is very well hidden until last moment, and last for very, very short time. Immediately after successful attack he disengages looking for next opportunity to attack.
How you deal with such situation? I mean how to discover the moment he decides to attack? And how to extend this short time when he is well engaged? Any particular training methods?
Please refrain from this nonsense IP/IS discussion..
Is there a practical difference between a good attack and a bad attack if neither hits? If uke makes a good shomen uchi do we find we can't enter in? If it is a bad shomen uchi does this also stop us entering in? No. If quality of technique is affected by the quality uke's attack then uke is in control; they can choose to defend themselves by making a bad attack knowing that it will foul up tori's technique.
When I spar in karate or kick boxing, as I do now and then, I just watch and wait and whatever he does I enter in. They make a kick, I push them over, they make a punch and I charge in. They're too busy making the strike to do much about my irimi. They're fixated on hitting me; their mind has stopped and so has their body.
The key to this, as I see it, is to train the mind. One has to be able to calmly stand and watch the strike coming in until it hits. When this can be done with detachment and indifference I find that there is an aweful lot of time to do something about the strike and so your timing improves. This is my experience anyway. If one tries not to get hit then one ends up doing things to avoid getting hit and so one is not concentrating on defeating the opponent which is the most certain way of not getting hit.
One must not become fixated on the attack; Takuan talks about this extensively in The Unfettered Mind
and it's a staple of stories from sword schools that students are beaten until they stop defending themselves and only then are they allowed to even touch a sword. Throw all thought of the attack away otherwise the mind gets stuck on it, throw away all concern for yourself and all the fear that goes with it; body follows mind and you end up reacting to the attack rather than being proactive so your mind must not be fixated on the attack.
The quality and form of the attack is then even more meaningless; it simply becomes the opening needed to allow irimi. Smarter fighters then try to move back and a good shove at this moment is most effective.