Or in other terms changing existing ones or creating entirely new ones.Ever wondered why one ryu does it this way and another that way ?It's because someone changed something.It is highly unlikely that any kata or ryu for that matter exists today as it was in it's original form.
As an example let's look at CHINTO KATA supposedly created by MATSUMURA after engaging in combat with a CHINESE merchant seaman who was washed ashore on OKINAWA.In CHINTO is a NIDAN GERI double jump front kick sometimes called a bicycle kick.MATSUMURA was body guard and instructor to the king of OKINAWA and in a sparring match the king attempted a jumping double kick against MATSUMURA at which point MATSUMURA soundly thrashed the king for attempting "such a risky move".
He must have felt strongly about it to risk not only beating his employer but also his king.Yet there it is in CHINTO a KATA that bears his seal of approval.Did he actually teach that ?Many researchers and authoritys say no someone changed something some say it is actually two rapidly delivered below the waist front kicks wihout the jump more of a "skipping" motion.
The "seaman washed ashore" overtime has become a catch all for sensei when asked "who created this kata" .A little investigation reveals that not even the JAPANESE //OKANAWANS are sure who created about 90% of KATA just that they were common practices in SHURI or NAHA or TOMARII the creators name lost to the mists of time
Should we change KATA or create new ones?This is something to be approached with hesitation a great deal of experience and insight or not at all.Many would say you must not change a thing as that is the traditional way.I call that "traditionalism" not tradition as study shows that elements have been changed on a on going basis for centuries. That is traditional.
Some concepts never change but conditions under which these concepts are applied do sometimes radically.A punch or a kick delivered 300 years ago is pretty much the same as one delivered today the method of getting it to the target may differ.In the ORIENT the concept is more rush in total commitment let the chips fall where they may while in the west our approach is geared more to the "stalking" approach of boxing and wrestling.A method kata was not designed for.
KATA interpretation should be geared to handle the "rush in get it done quickly" concept as this is the mode of most street attacks self defense scenarios.A street thug or rapist or mugger or any variety of sociopath out there does not want to trade jabs with you or in the words of MACYOUNGhttp://www.nononsenseselfdefense.com/traditionalMA.htm#streetfighting want to fight you he wants an assasination .To try and gear KATA bunkai to sport application renders KATA useless.
All this must be considered when changing or interpreting KATA or creating new KATA.
Grossman popularized the sheepdog metaphor. The idea is that there are sheep-- generally nice and productive but not what one would call hard core. And the...