No I always heard that the WTF/KKW was much bigger than the ITF & I think it is, but that the independents far outweighed them all & put together.
There probably really is no way to tell which governing body is bigger, but if I had to
guess I'd agree that it's probably the independents. There are many schools where the instructor is either certified by the ITF or the KKW but the students are not. There are many schools that aren't certified by either body.
One of the problems with coming up with even an estimate of who has more is the propensity many people have of extrapolating anecdotal evidence into a worldwide generalization. Not a lot of ITF schools here in the U.S., for instance, but go to Poland, the Czech Republic, or Argentina and they're quite common (and produce top notch competitors, too). But do those countries mean that the ITF is bigger than KKW or even independents? And just because I grew up in an area where there were very few KKW school doesn't mean anything when it comes to determining who popular they are on a country or even world wide level.
I remember reading a study somewhere that had the USTF, the ITF NGB having around 10,000 members & the USTU, the WTF NGB having some 20,000+ subscriptions that it sent to its registered members. Those numbers paled in comparison to an extrapolation to the independent number estimate.
I'd be interested in seeing that study. One of the things that limits it, of course, is that it relies on numbers of enrolled members in the respective NGB's. While this is good to give a ball park figure I wouldn't make too much of it. IIRC, there was nothing mandating membership in the USTU for KKW certified people. Additionally, you don't mention the KATU membership which was a second ITF body. There were always some people in the U.S. (and otehr places, I'm sure) that were members of the ITF but not of the USTF (or of KATU).
Additionally, both the ITF and the KKW only certify black belts. The best one could hope for would be an accurate count of yudanja (and given the stateof the ITF that's not going to happen for them). But if you want accurate numbers shouldn't you include color belts? And if so, do you include 10th gups even if they've only been training one night?
Lots of problems trying to just get a head count.
Pax,
Chris