Hey guys!

I'm an intermediate drummer and after gaining some speed I've noticed that my left hand is always climbing up the drumstick.

I've been going through Allan Dawsons 4 way coordination exercises and this is where i really notice the moment of my left stick, when trying fill in triplets with the left hand.

Ive noticed my sticks are rested on the second joint of the index finger not the first like everyone says it should be and my thumb seems to slid off to the side so its not braced against stick. My thumb is not staying put on the stick where the center off thumb is. I'm wondering if its more of a strength thing or if its technique i need work on, and if so what are some exercises i can do to help me keep it in position?

Every time i try and keep the meatiest part of my thumb (center of the thumb) braced against the stick it always seems to move back to the side of the thumb and the stick back to the second joint of the index finger.

any thoughts? I'm sorry if this post doesn't make much sense but i'm have a hard time trying to describe what actually going on I can send pictures if anyone wants to help out!

Thanks for your help!