Not a black belt myself, but agree with GP. Sparring frequently tends to be "people trying to murder each other on the mats in pursuit of their egos". There's a level of dynamism in good sparring that can immediately get shut down if one or both practioners are overly motivated by "winning". You need to take a lot of risks to learn in practice even if it means getting clowned by someone who you could beat if you had to, but you do see people sticking to conservative games in order to dominate. Which often doesn't teach them (as they aren't learning new aspects) but it also doesn't teach their opponent (as it's very hard to learn new stuff when trapped in someone's well-rehearsed "A Game").

The advantage of positional sparring (i.e. go from one position and stop when someone gets out of it to some outcome - not necessarily a tap) is that everyone gets to sharpen a single position. The ego motivation isn't as strong there as it is with full sparring.

Yes, that's my approach when I am teaching. Positional sparring is way superior to free sparring for learning. Lower stakes, people are more relaxed, the same position is presented multiple times and that's where learning happens.

And I explain it to students beforehand. I say to students: there are interesting games going on in positional sparring and one is that who is trying to escape (say, from mount) is in a better mental, but not physical, position. You are already mounted, now if you "lose", that's ok, but if you "win" (that is escape the position or finish), it is a big win! And for the who's in mount, finishing is ok (already in mount), but letting the mounted escape is a big "loss". Winning when all, including yourself, know that anything else than winning is a bad loss, is being in the "ugly zone", like Dave Alred says, high pressure, low margin for error, when things are not pretty. But that's where one learns (it sounds like it is high stakes, but it not, because the activity/drill is repeated multiple times).

I do positional for takedowns, side control, mount, from flat half guard, favorite guard (and I say, this is your favorite guard, you should be hard to pass!).

I like this approach. I always wanted more positional sparring and less free sparring. I've noticed that high pressure "expected to win" situation (which, frankly, I love in mount/side control as I've got a better game, relative to expectation of a submission, while my back control/submissions game underperforms).

I've noticed the defender from 'bad positions' does better in specific training than they do in sparring in the same position, probably because they can put everything into getting the "W" - while the attacker in sparring would probably be cooking them or switching to a different position.

There are still weird ego-driven things going on here. My least favorite: being on bottom open guard and having people disengage and run around to win - it's like, bro, if we weren't positional sparring I can just stand up and we can see who has better takedowns. Personally I think this one should begin with at least one grip to avoid time-wasting.

Do you do the "5 minutes on top / 5 minutes on bottom" approach? Or alternating? Or "3-5 people down with a line of people coming in". I think each of them has good/bad elements (without "3 wins and you're out", the latter tends to reduce to the top 3 students annihilating the newer people and not facing each other :-) ).

Yes, I have found positional sparring to lead to the quickest improvement from blue to black (novices have different needs, typically)

"I've noticed the defender from 'bad positions' does better in specific training than they do in sparring in the same position" - It varies, but my rationale is that when somebody is passing your guard and then mounting you, you are typically dog tired and mentally you go from bad position to worse. In positional sparring, the guy in a bad spot starts from that position, so mentally is in a good place, and not as tired or positionally compromised.

"My least favorite: being on bottom open guard and having people disengage and run around to win" - Agreed, like typically new guys not engaging and wasting a couple of minutes by running around. In that case, I simply say, "come here my friend, let's practice", and they start getting in. And the same when I am the coach, I just encourage a more low-stake environment (which does not mean low effort or low quality) and I must say that I never got any pushback. "Let's practice, that's how we improve".

"Do you do the "5 minutes on top / 5 minutes on bottom" approach?" - I typically do two bottom and two top for each position (one top and bottom with one person and one top and one bottom with another), with rounds of 2 to 3 minutes, encouraging students to push the pace (2 minutes go by real quick and I don't like wasting opportunities to improve). My coach likes the line of people getting in, winner stays in, and 3 wins and you are out.

I think that both have a place, but I have prefer the two minutes round because it creates good competition (you pass my guard, we restart, now I am trying to avoid that same pass, while with the line there is not this immediate opportunity of a comeback).

Thanks, good thoughts there. I'm off BJJ for a while (lockdowns in Australia), and won't be getting to decide how classes go for a long time if ever, but it's good to hear people thinking about it rather than blindly replicating "what I saw in Brazil once".

I've only been training a little over 3 years (definitely not a BB), but maybe the BB meant there are many different types of sparring. Many (most?) schools warm up, show a move, (maybe drill it), then let everyone spar away. The problem is when sparring the person with more skill will severely limit the positions the less skilled person sees. If the less skilled person happens to be very strong or athletic they can in turn limit the positions the more skilled person sees just by holding on, which turns the sparring into very limited training value.

For me, what has helped really learn is drilling. I know lots of BJJ people hate it, but I like winning and drilling works. Even those who hate drilling will admit it.

Positional sparring. Start in some position and work from there. I purposely let less skilled people start in advantageous positions so they get to work from a dominant position (where most submissions come from), and I get work escaping from bad spots.

Finally, flow rolling, which at higher training levels doesn't look that different from sparring. But, it's sparring where both sides give and get so that each sees many positions. At my level we also move much slower. Think about how hard it would be for someone to learn Chess if all they played was bullet chess? You need that bit of time so that your mind can start to build patterns, and then speed up.

I'm fortunate that I lucked into a school that teaches a bit differently.

EDIT

I should add that free for all sparring still happens, it's just not the focus of every class. Open mat days and end of class is often when people go more free for all.