Randori in common parlance is "sparring". It's a very important part of judo training. Through randori, you get to test out your skills and see if you can get your techniques to work against a resisting partner.

Here are eight common randori mistakes players make that will prevent them from getting the most out of their randori experience:

1. Talking during randori. Randori is when you "play" judo. In sports, you spend some time doing technical training and drilling, and then you play the sport. In badminton, you try to smash the shuttlecock onto your opponent's court to score points. In swimming, you swim laps in a pool. In football, you try to score goals. When you play a sport, you don't talk. You focus on playing that sport. Can you imagine someone stopping in the middle of badminton game to ask their partner how they can smash the shuttlecock better? Yet, beginners do that all the time in randori. Midway through sparring they will suddenly stop and ask the more senior player: "What's wrong with my gripping?" or "How come my techniques are not working?" or "How do I deal with your stiff arm?" You don't ask these things in the middle of randori. You do it after. And if you are the senior player and a junior player talks or ask questions during randori, you should say: "We fight now, talk later."

2. Treating randori as shiai (competition). Some players literally treat randori like it's the final of the World Championships. When you treat randori like a competition, you do everything you can to avoid conceding a score. You are closed up and careful not to give any scores away. As a result, you don't try very many techniques. You play it safe and defensively. That's no way to do randori! Randori is a time for experimentation and figuring out ways to make your techniques work. It's also when you discover what doesn't work. You won't be able to do any of that if you treat randori like shiai.

3. Avoiding senior players. Some beginners think it's dangerous fighting a brown or black belt. Actually these are the folks who are skilled and experienced enough to take care of you. You are more likely to get injured fighting another white or yellow belt than you are a high-level belt. For one thing, the white or yellow belt might not even know what's legal and illegal. They might do something that injures you because they don't know it is not allowed. This won't happen with an experienced player.

4. Spinning out of a throw. Experienced players and competitors do this all the time. It's instinctive for them to spin out of a throw to avoid conceding a score. But experienced players know how to do this safely. Beginners don't. If you are a beginner and you get thrown, don't try to spin out of it. Take the fall. If you try too hard to avoid conceding a score you might sprain your back or worse still, break your arm trying to avoid landing on your back. Don't do this. Take the fall, get up, and resume the fight.

5. Declining to do randori. If you are asked to do randori, you should never decline unless you are injured or sick (in which case, you should inform the sensei beforehand). It's consider rude to say no to a randori request. And if you make a habit out of refusing to randori, it is you who loses out. The more randori you do, the better you get at judo. The less you do, the worse off you are. The players who make the best progress are the ones who relish randori. They want more, not less.

6. Fighting everyone the same way. If you fight a person your size, it's different from fighting someone much larger. What works against a smaller opponent will not necessarily work against a bigger on. And in all likelihood, if you try a small-player technique on a much bigger player, you are likely to get countered at best, and injured at worst. On the same token, if you fight a much smaller or weaker player, don't use the same technique you normally use against an opponent your size or bigger. Don't squash the small player, who is much weaker and probably more fragile. Instead, use the opportunity to practice stuff you don't normally have the chance to try, like foot-sweeps and all kinds of ashiwaza. It's not like ashiwaza is easy to pull off. So, if you meet someone smaller/weaker, try your ashiwaza on them. Mutual benefit means both players gain from the exchange. So, don't get injured and don't cause any injuries. Adjust your playing style accordingly.

7. Not following up in newaza. If space allows and the sensei says you can do newaza follow-ups, you should. After you do a throw or after you get thrown, follow up in newaza, to make it a habit. A habit is not something you can turn on or off, like a light switch. In order to make it instinctive or automatic, you need to force yourself to do it repeatedly. After a while, it becomes a habit and you don't have to remind yourself to do it anymore. You just do it. You want to foster good habits, like transitioning into newaza once the fight goes to the ground. So, don't stand up. Carry on fighting on the ground.

8. Not attacking an uke on their knees. If you knock uke down and they land on their knees, it's still tachi-waza as long as their elbows are not on the mat. Don't walk away and let them get up. When uke is on their knees, that's when they are most vulnerable for a throw. They can't really maneuver much. They can't grab your legs. There's very little they can do. So, attack them, and get the throw. Again, make this a habit. Always follow up with a throw when you get uke to fall down onto their knees.