mathewjgano

As another example, knowing the history can help improve some people's ikkyo simply by articulating the whos and whens of training, adding to an awareness of the options for experiencing different perspectives on it. The transmission of whatever it exactly was O Sensei did might be difficult for all I know, but at the very least we can glean some idea from the different schools of practice which spun off the arc of his own training.
History can be described as a description of past behaviors and things; as Chris said, to whatever extent we can glean the history of O Sensei's study, through the historical compilation of the various axioms and images and the people who have gone before us to offer their subsequent interpretations, we can apply it to our own practice. Reading the most detailed and accurate history possible will not, of course, give anyone any direct skills at ikkyo or any other movement. They can only be applied to the strategy of shaping one's training...which must take place with people who are sincerely refining their understanding, too.
Not knowing your history doesn't mean you can't have a better ikkyo; it's not required for the physical practice, but it can help inform the overall process.