I train at a non-10th Planet school (I'm moving to 10th Planet St-Paul in December), and about once a week we have a guest instructor come in and teach. I was rolling against a kid half my size (I bet him dinner that I could triangle him) and ended up in half guard. I threw in the lockdown, as I always do, and prepared to electric sweep. The guest instructor (purple belt who owns a nearby MMA gym) tells us to stop and spends the next hour explaining how the lockdown is a gimmick that only works against people who don't know it, and should only be used on a situation by situation basis. His argument is you don't want to remove your mobility and limit sweep selection to the handful of lockdown based sweeps. He also said based on my size (6'1", 275 college lineman) the lockdown doesn't support larger legs well. While I understand his logic, I disagree, as I haven't had trouble against guys who are my size. Usually the tightness allows me to tap opponents based purely on pressure. All that said, I'd like to ask you guys the question, in what situations would the lockdown be unwise?
Edit: All of this within the context of tournament jiu jitsu.
Edit: All of this within the context of tournament jiu jitsu.