Firstly to explain the two roles in Judo, Tori is the person performing the technique so will be the attacker, Uke is the person receiving the technique so basically the defender. Everyone wants to be the Tori, performing the throw, applying pressure in the hold down, applying the pressure on the joint or the neck to cause the armlock or strangle but without Uke, there will be no Tori.
As an old Judoka I have obviously been the Tori thousands of times but I have also been Uke thousands of times as well. What many do not realise is that being Uke is still part of the learning process as much as being Tori. A saying you will hear a lot at competition and you may well hear it from me, as it is one of my favourite sayings "you didn't lose, you gained experience". OK the person I usually say this too is the person that has just lost but the point is that losing a competitive fight does include a learning experience. How often have you seen someone caught by a move and say "I'm not falling for that again". This does not mean that I go out at competitions to lose and gain experience, no of course I go out to win and drink the blood of my enemies. Ok these days I leave out the blood drinking, Judo was more hardcore in the eighties, LOL. What does happen a lot more now at competition is that usually someone will have a phone and will probably film your fights. This is really great as afterwards I can sit and watch my fights and spot my mistakes and missed opportunities. I can often see errors in the wins as well as the losses, so luck on the day is still a major factor.
I guess what I am really trying to say is that you will spend nearly 50 percent of your training time as an Uke but don't look on this as lost time as you can still learn from the experience. You can feel how the Tori sets up and does his throw, this will teach you how to feel the attack is coming when in competition and if you are aware of the next attack, then you can defend it. The best example of this I can give is if I go back to the mid nineties when I trained at a club on the outskirts of Romford, which was run by Terry Adams, who was an amazing Newaza technician. One Friday night a then much slimmer version of me, turned up for my normal Friday evening training to find that Terry had organised a visit by Sensei John Cornish, who I was aware of as he was one of the technical advisors to the BJA and I had instructional books with his name on. So I was immediately pretty excited by his visit. As we lined up I noticed him do that thing that old sensei do when they have a new class of people in front of them, he was scanning us all and weighting us up, Uke hunting. His eyes settled on me and he beckoned me forward from the line, YES he had taken a grip on my gi, it was going to happen. He spent awhile breaking down the movement into his first throw, covering the Kumi-kata, the grip, the Kuzushi balance breaking, the Tsukuri positioning and then Kake, the technique. It was all done so perfectly, I flew like a bird and landed like a feather. He was a mature man at the time and I was a keen young warrior but he threw me with such ease and precision. After the first throw there was a little grunt of satisfaction from the sensei that I think meant that I had passed the test as a Uke as he would go on to throw me about all night as his Uke but that was not a hardship as each demonstration in front of the class was a demonstration of the pure art form of Judo. I learnt so much as a Uke that Friday evening and carry that knowledge forwards today, still using methods today that I collected from a master nearly three decades ago.
These days I am the one out the front teaching much of the time and I try to carry on that skill and knowledge that was shared with me in one night of being a Uke. A little while ago I attended a coaching course and was asked to demonstrate a tai-otoshi, so I looked at the group of Judoka gathered around me looking for a possible Uke to use. There was a young Judoka who looked very fit in that competition trim sort of way and I asked him to be my Uke and then gave the demonstration. Later as I was asked to demonstrate again the young Judoka immediately stepped forward and I asked "you volunteering to be my Uke again ?", he replied "I like the way you throw". I hope this was because he felt the skill and art of Judo as he acted as my Uke, that I have felt along my Judo path as I have acted as Uke for those great sensei's of the past like sensei Cornish.