Tuesday, January 3, 2012

Don't try this at home

Thank you to Al B Here for his comment on my blog, asking about yesterday's post.

He wanted to know why I roll over the opponent when she is in this position.
I think I did not make it clear enough. What I am doing is DIVING over the opponent.

There was a game we used to do when I was a child which illustrated this perfectly. It is also strongly discouraged by all of the judo organizations for the very logical reason that it is dangerous. It looks dangerous, although I have never known anyone to get injured doing it. The same can be said of climbing trees, diving off a pier, swimming at Johnson's Shut-Ins, and swinging on a rope swing and letting go to land in the middle of a river with a strong current, barely making it back to shore and starting all over again. All of these are things I had fun doing as a child but other people died doing them.

Here is a video from Fox Valley Judo showing adults diving over a crash pad. This is kind of  the motion you are going for. It's somewhat safer than the drill we used to do because the person is landing on a crash pad. Here is another video that has players diving over a standing person and then over some mats. In this one, too, they land on the crash pad.  Both of these have the player diving up more than over.

The drill we used to do is not shown anywhere that I can find because it is stupid and dangerous, no doubt. What we did was have a person bent down like Ana is in the picture above, and then we would do a forward roll over them.  After the whole line of kids did that, we'd have a second person kneel next to them and do a rolling fall over both people. If you chickened out, or if you missed and ended up falling on the second person, you were out. We kept adding people until only one person was left.

I still did this drill with my own children. They can't sue me because if the do, I'll put arsenic in their toast and that will be the end of that.

ANYWAY .... the point is that you do a DIVING break fall , stretching your body out and then rolling back like a regular fall. Your MOMENTUM carries you over

and brings your opponent with you as you can see here.

A second important point is that even with the momentum, if your opponent is MUCH heavier, this will not work. Say I am 123 pounds (56kg) and my opponent is 220 pounds (100kg). I'll probably get him somewhat off balance but I doubt I will pull him all the way over. 

This technique works fine for competition because it is by weight division, and against a person of equal weight, with the momentum added by the diving motion, I can always pull them over and up.

As you can see from this helpful wikipedia entry (give them money, I did), 

Kinetic energy = 1/2 mass times velocity squared 

This is why the diving part is so important. The more I can increase my velocity by diving out, since this value is SQUARED, the greater impact on total force applied to pull my opponent over.


Al B Here said...

The diving makes a difference, for sure. I get the physics aspect of it. I was more curious about why you opt for the higher risk movement, rather than something lower risk. I'm sure the opponent on the receiving end is disoriented by the attack. Is that the appeal?

Ibai Peña said...

Hi AnnMaria,

Why do you prefer this technique to this other okuri eri jime? (Knee??)

Starts from the same position and seems safer.

BTW I used to do the same last standing man game with the ukemi. Never look too dangerous.

Dr. AnnMaria said...

The video you showed was not focused on competition. In the move that I am doing, you can pull back and pin your opponent if you miss the choke. I always look for something that has a natural transition to a combination. That is, I always have a Plan B, a Plan C and a Plan D.

Also, if you pull your opponent back into a pin, the clock keeps going, so if it is near the end of the match and you haven't got the choke yet, two things are happening. One is that you get extra time. The other is that if you ALMOST pin someone for ippon that means you got a waza ari, so I can get a partial score even if I miss the choke and the person eventually gets out of the pin. I'm a statistician by profession, you know. I always like to maximize my odds.

Dr. AnnMaria said...

Ibai -
I agree with you about the ukemi game, by the way, but all the organizations say it is too dangerous and we should not do it any more.

Al B Here said...

I'm somehow not surprised that you work for the highest probabilities. As always, your reasoning makes perfect sense once it's spelled out to my neophyte judo brain. :)

Anonymous said...

We still do that rolling ukemi drill at our club. It's the kids' favorite game. We use crash pads now. When I was a student (1990s), we did not, it was done only with the tatami, and my sensei say they did it outside on concrete pavement. (1970s/80s)