"Juji gatame? What the hell is that? A new type of test for comparing nested models? I've never heard of it?"
The judo people, on the other hand, are asking,
"Models have nests? Can't they afford to buy houses with all that money they are making? I mean, they sure don't spend it on food, and they get their clothes for free."
Well, the two did intersect recently when I read this blog by John D. Cook who is a pretty well-known blogger on mathematics and statistics. Those of you who think that is an oxymoron should just shut the hell up and those who don't know what an oxymoron is, just skip on to the next paragraph which is ...
John said that the key to success is more often to do well at several different skills and combine those to be something remarkable, rather than to be world class at a specific skill. He gives the example of Scott Adams (the cartoonist who does the Dilbert script), who was not a great writer and not a great artist but combined the two to be a great cartoonist.
When I read that, my immediate thought was the opposite is true for being a world class athlete. You need to be good at everything, better than good, really, and GREAT at something. You can't be just great at matwork and have so-so standing technique because once you get to the top level you'll be thrown and never get to demonstrate your amazing matwork.
You may get farther with outstanding standing technique and lousy matwork, because they do make you start the match standing up (whose stupid idea was that rule, I'd like to know). Still, at some point you're going to end up on the mat.
I can think of players I knew who were very well-rounded. They had solid standing technique, were in good physical condition, respectable matwork. They were good all the way around. Many of those people placed in national championships. A few even made an Olympic team (which is easier to do in the U.S. than in many other countries because we don't have that many people competing in judo). None of those people with a "package" of skills were people who won a lot of international medals.
When I think about people who were world and Olympic champions, they are people like Gerda Winklebauer who choked damn near everybody, Koga, who threw everyone with seoi nage, Osawa, who could foot sweep anybody (I should know because when I was a student at Waseda and he was probably in his forties already, he threw me approximately 246,786 times).
Right now, if you look at how Ronda is doing in mixed martial arts, she is armbarring everyone who comes near her. The only reason she hasn't armbarred her dog, Mochi, is because, strictly speaking, dogs don't have arms.
So, the answer to should you specialize seems to be, mostly, "Yes."
But ... I remember a time when Ronda was much younger when she threw everyone with left uchi mata. That was her throw and she did it from a high grip, from around the hip, from a lapel grip. On her way to her first Olympic team, she was fighting a very good player in a major tournament who had obviously trained for this match. She bent over and Ronda could not get into her uchimata to save her life. So she dropped down and threw for ippon with drop seoi nage.
Coming off the mat, the player went up to her coach and complained,
"I thought you said she didn't do anything but left uchi mata."
"I said she didn't do any other throws. I didn't say she didn't KNOW any other throws."
It's funny to think of now when everyone associates Ronda with matwork that for years she did pretty much beautiful stand-up judo. (And then I ruined it by teaching her juji gatame!)
It reminds me of some not very good western I saw probably 20 years ago where a rich Australian rancher brought to his ranch someone from the American west who was very famous for his skill with a rifle. In the end, the rancher insisted that they have a showdown, which ended with the American drawing his six-shooter and putting a bullet into him. As the rancher is dying he says,
"I thought you couldn't use a hand gun."
To which the shooter replies,
"I said I didn't. I never said I couldn't."
Anyway, it was something like that. My point being that you want to be world class at something - specialize - but not to the extent that you can't pull something else out of your back pocket.
So, maybe John Cook had a point after all.
P.S. This was meant metaphorically and not that you should literally pull a hand gun out of your back pocket to win a match. That's against the rules. Unless you're in a cage fight in Texas.)