In college I was "taught" ( pushed maybe? ) to choke / move the ball back in my palm to take off velocity. When you see a guy perfect it it's a thing of beauty, ball really looks like it backs up. But I just couldn't pull it off. So playing catch in warmups I experimented with other grips, and found that by getting the ball out on my fingers with a very loose 2 seam grip...and getting my fingers on the 1st base side of the ball ( sure didnt know what the heck pronate meant ), I could effectively take off velocity while maintaining fb arm speed. Most of all, I could consistently control location because of the feel I maintained on my fingers. And as I tell pitchers now...if you can't throw the change at 2-0 or 3-1 consistently for strikes...you really don't yet have a change up.
I'm all about results, so if a kid has a method that is effective I certainly don't introduce or force mine. But I've always got it in my back pocket, and it's amazing how easily the kids pick it up.