10 Sec. Drills

10 second drills are a great way to train Judo and even other grappling sports.
The key idea behind these types of drills is that you have to accomplish something - throw, pin, submission, ... in 10 seconds.
You have to do it right and you have to do it repeadetly.

Few examples:

Line up fight

One player stays in the middle. Other players rotate swiftly every 10 seconds.
Player in the middle must attack on every rotation. Rotating players do what they choose - attack, defend, stall ... Drill simulates high intensity match, and how would you play it to win.
Attack, attack, attack.
This is a gruelling drill, but it prepares you to be a "Dobermann" in the competition.

10 sec Juji Gatame (Cross Armlock)

One player (Uke) is on the ground with his hands very loosely close to each other.
Another player (Tori) is standing close to Uke's shoulder.
On the sign 'go' or 'hajime' Tori has to secure the Juji Gatame and Uke has to defend it.
This is a great exercise for both. Tori has to learn to be fast and accurate, and Uke has to learn how to effectively get out of the trouble while on his back.

In our club, we utilize 10 sec drills for the wide array of excercises. We drill grips, pins coming from the knees, escapes, turtle turnovers, chokes coming from the back - all utilizing this method.
We found that these short-timed drills are great for improving the quickness and accuracy which is important for both competition and self-defense situation.

WARNING: These drills may result in a higher rates of injuries because you of the "rush" associated with the time pressure.
Do not practice these drills until you have mastered the moves in a slow, controlled fashion, and
even then have them executed in a fully supervised environment.

CREDIT: I need to give credit for this idea for 10 sec. drills to Ann Maria, World Champion and US Olympian Rhonda Rousey's mother, who shared this training style with few of us on the Judoinfo forum.