Free practice trains technique. It is based on the philosophy of, and is the best way to learn, judo. Through randori, the student of judo learns to master technique, to move on to advanced techniques, and then on to reach enlightenment in "the way."
For those who are considering learning judo, they must understand that randori is indispensable. Only with randori will you overwhelm the opponent's strength, confuse him, and restrict his ability to adapt to another technique. The difference between your capability and that of your opponent's lies solely in the accumulation of everyday training and perseverance.
The core of judo is to enter the "way" through "technique," and this absolute truth recognizes the necessity of randori. It is fundamental in training to consciously and continuously change from one technique to the next, until victory. Likewise in randori, one must begin a technique, cause the opponent's posture to change, and execute another effective technique at precisely the right moment.