Ditto^^
I was blessed with a basketball coach in the late 60's early 70's who was a fundamentals and conditioning fanatic.
She introduced us to Valparaiso technique for free throws. The gist is the fewer moving parts the less opportunity to screw up the shot.
Article about it, we had the booklet in the photo.Those on the team who used this method shot high 90's% in games. If you shot less than 85% in games you had to be golden in some other aspect to get on to the bench, much less in the games.
Since we had to run laps for missed free throws/passes/fouls/etc. there was that incentive, too.
momlaw