Looks like Tbombz is describing the regular wide grip chin, which some people find a much superior exercise than lat pulldowns.
I've always found that pulldowns and machineS are just as effective as chins, and prefer them personally. They all hit the lats well but slightly differently, so it's good to rotate them all in and out of the routine over time.
Part of what makes chins effective is that it's tough to compromise the intense muscle stimulation-the resistance is already very high, and it's tough to compromise form on chins enough to make them ineffective. It's alot easier to compromise on resistance and form on pulldowns, so you have to be more aware of that to make them similarly effective. You want to keep the resistance high, like bodyweight chins. On form it's easier to compromise on pulldowns-arching the back or cheating is ok i've found, but
not leaning back during the movement, which seriously erodes the effect on the lats.
I get just as good lat soreness and effect from either one, both good and slightly different from one another, if the above is taken into account.
As far as hand spacing, Arthur Jones suggested using no more than a medium grip decades ago, so Yates as a HIT disciple probably knew that as well as learning on his own. I went to narrow and medium grip around 1980.
