Loyalty is a big part of the team aspect of Brazilian Jiu-Jitsu, but why? And does it really matter?
I think the most important thing to consider is that loyalty should be an important part of everyone's life. Being a loyal person is a good character trait. What is loyalty though? To me it's a two way relationship, not just one person being loyal to another. Both or all people involved in anything should be loyal to each other, they should always look out for what is best for all not just themselves and should treat everyone involved fairly. Judging whether people are truly loyal is the hardest part.
Before I talk about jiu-jitsu I need to say that I am talking from the perspective of someone who trains under an instructor (Chris Rees) who is a really good person and instructor, so my feelings on things are shaped by that. I will do a piece about why it's important to choose where you train wisely at some point in the future.
So why is this important in jiu-jitsu? Students are just paying customers right? They should be allowed to go where they want? I feel bad for anyone who has this feeling towards jiu-jitsu. I love training, teaching, competing and everything else that is part of jiu-jitsu, and being able to be amongst a group of really close friends doing all that makes it even better. I plan on doing jiu-jitsu until I am dead or can no longer get myself onto the mat, I want to be surrounded by people I've known most of my life when I'm 65 not be the outsider at loads of different clubs. I also want to do everything I can to help my team mates, not spend some time training elsewhere. If you really are just paying for a service at your academy I feel sorry for you. If all you get is the class time while you're there, no other support, no competition coaching, no friendship nothing but the lessons themselves then you are at a bad place to train.
Other people make the argument that if you want to be the best you have to always seek out the best training. Fair enough, but what level are we talking about here? If you are a high level competitor with aspirations of winning the adult black belt Mundials then you do need to have a very high level training environment, but how many people are in that position and who got them there? For most people, any genuine academy with good level of instruction/competition performance will be able to give them the training they need to win anything but major titles. Anyone with the potential to be a world champion should be able to find training from their instructor's lineage... which is another reason why loyalty to your instructor is important.
But what does it mean to be loyal? Does it mean you can never switch teams without being considered a traitor? To me loyalty in jiu-jitsu is the same as any part of life, it means you should do everything to try to improve the team not just yourself. You should support your team mates and instructors, and they should do the same for you. Not all instructors deserve loyalty; some will only see their students as income sources, some will neglect their duties as an instructor, some might have worse problems... there are definitely cases where students should change team. Plus some team changes will happen by necessity due to either the instructor or student moving (although when both are high level there is no reason for this to cause a team change). It should be rare though, and if you do have to switch teams make sure you pick well.
One of the worst things I've heard proposed is that it's ok to leave your instructor and open your own school. I am sure that every instructor out there will be happy to help one of their most senior students to start teaching, so get yourself to that level and ask your instructor. If you're not a senior grade why would you want to start your own academy? It will only end up worse for all involved... the instructor loses students, the students lose high level instruction and the students of the new academy get a lower level of instruction than is available elsewhere. "But what if people want to make money from it?" ...tough. Money shouldn't rule things, don't screw over your instructor because you feel deserving of benefiting from their hard work. And if you love jiu-jitsu enough that you want to make a living off it, why does diluting the training available and starting an inferior academy seem like a good idea?
None of this means people can't train at other academies/affiliations while travelling, I have always welcomed any visitor from any where and I think any legitimate instructor would.
Basically, find somewhere enjoyable and successful to train and stick with them.