Kata vs Randori…
There was a time when I believed that randori - being what set Judo apart from Jujutsu, was the key to learning Judo. I felt, as did many sensei, that you should do your warmups, then spend 70-80% of the class time in randori. (With the other 20-30% spread among ukemi, uchikomi, kata, and instruction).
Down through the years I’ve greatly modified that original impression. I’m of the opinion nowadays that you should spend far more time doing uchikomi & kata versus randori. While I’d be hard pressed to defend any particular breakdown, doing 5 times as much uchikomi as randori seems appropriate to me.
Even when you do randori, I think it’s essential to do at least half or more of your randori in a cooperative (rather than competitive) mode. “Exchange” randori, where you trade throws, and provide only about half of your normal defensive skill - is a valuable means to improve your Judo.
Many Judoka approach randori as a non-formal version of shiai. But in order to practice your Judo skills, you should be looking at a good portion of your randori as an opportunity to ‘play’ Judo. When you were a child, play is where you learned the skills to be an adult. You learned what was appropriate, what was allowed, what worked, and how to influence others.
In Judo, doing randori in a loose manner (and not as shiai), can be the ‘play’ that Judoka need to improve. This is where you learn new combinations, try out new techniques to see if they ‘fit’ your style. While there is always a place for hard randori - it is the final test just short of shiai, it should be less than half of your randori practice.
One Hachidan at the Kodokan gave as his reason for his superb ability at Judo was his constant practice of rarely doing randori with equal or better partners… he did most of his randori with those of lesser rank. Such a way of practicing gives the better Judoka a much better chance to improve his skills by actually doing them.
Sport coaches have long recognised that the best way to improve the performance of any particular skill is to do that particular skill. And what is uchikomi but the continued practice of a particular skill? What is non-resisted randori but the practice of performing your skill in a random situation?
Give it a try… ask your partner to give only half resistance - and to ’swap’ throws… see if your shiai (or hard randori) skills don’t improve!