What I would suggest is this. If you applications are not hands on as in holding or controlling it is not bunkai. If you technique in the bunkai was to fail, the next move in the kata should lead you into the next application. If it doesn't you are practising an application, not a bunkai. And, more controversially, if your application is a 'block' I would again suggest your interpretation is not bunkai.
:asian:
K-man, I respectfully disagree with your last paragraph. While holds, joint locks and take-downs (what I interpret "holding and controlling" is) are something I was taught is essential and part of my style by my teacher, I do not believe that they are the only possible bunkai. I also do not particularly agree with the point of view of some that bunkai must be confined to a direct sequence in a kata. In other words, I do not believe for ex that Passai moves 1-4 must be done in succession in order to make an explanation. You can mix and match the opening x-leg back-fist with a later move is what I'm saying.
But maybe this is just too much detail!
In this context holding and controlling did not include joint locks and take downs at all, although if a technique was successful it may end with a joint lock or take down.
In reality, bunkai is what it means to you. If you believe, as I do, that each kata is a fighting system, then there are certain assumptions that you can make. Firstly you can enter and leave the kata at any point. In other words you may be grabbed, you respond, the guy is struck, he goes down ... game over. However what happens if the guy blocks your strike? In my understanding when you responded to the attack using your bunkai you would be restricting his movement in some way so that his response to your strike is limited. In this case he lifts an arm to block the strike. This is in fact within the bunkai a 'predicted response' as his other arm would be restrained in some way. If he misses with his block he is hit to a vital point (ie neck, jaw, temple etc) and if he blocks you can control that arm (because you have trained for that response) and move to the next step of the kata.
Secondly, to achieve a 'predicted response' you must be engaged. If your opponent can move away or strike with either hand or kick you with either foot there is no way you can be certain of what is going to happen. Once he attacks, or you move pre-emptively, and you engage you can move into the appropriate part of the bunkai.
Thirdly, there is no 'one real bunkai'. Bunkai is what makes the kata work for you. You can get ideas from other people and you can be taught various movements by experienced people but at the coal face it has to be the tools that work for you. I believe that is why 'the real bunkai' was never passed down. It never really existed. That is why the kata was passed down. All you need to develop the bunkai is contained in the kata.
(The alternative view is that kata are just a collection of techniques. IMHO, if that is the case then it makes no sense to me to study kata as you can always look at techniques individually and you can develop drills that combine techniques.)
As to Passai kata, I have no knowledge. I did watch it on video and see no reason why it would be any different to any other kata. But I am not suggesting moves as you described as 1 to 4 need to be done in succession for an explanation. You can give any number of explanations for a particular move and you can put 2 and 4 together if you want .. but you are no longer doing the kata so that is not kata bunkai, if that makes sense. I would suggest that if you are not using the techniques in the kata in order, then you are using the kata as a collection of techniques and not a fighting system.
How any person interprets kata is up to them. If it makes sense, go for it. For many years I did not understand the kata. My teachers had no understanding or knowledge apart from the basic form that was required for grading and competition. At that time, if asked, I would say the kata was a collection of techniques. But for me the light came on when I saw what George Dillman and Iain Abernethy were teaching. When I started training under Taira Sensai it was like starting again. It was a whole new world.
:asian: