Originally Posted by: paulcavaliereIs it still advisable to place thumb pressure behind the neck for fretting on an electric?
Yes. You are correct that it is sometimes necessary to adjust depending on the technique required. For example, sometimes you need you thumb to anchor on the top edge of the neck as a means of getting leverage when you are bending the upper strings.
But in general, the thumb is for opposable pressure.
https://www.guitartricks.com/lesson.php?input=12188&s_id=605
See here for an example of using your thumb as leverage to bend.
https://www.guitartricks.com/lesson.php?input=20406
Good question!