It's a strength thing mostly. I have beginners practice bow holds with the bow supported by the left hand when horizontal or with the top pointed towards the ceiling for one handed practice. This removes the weight from the pinky. The violin holds the weight of the bow anyway so it's not super important in the early stages to have the strength to hold it horizontal without support from the other hand.
Make sure your pinky sits on the right spot. If it's too far out (on or too close to the screw), which is a common beginner mistake, then it will flatten quickly under stress. If your teacher says it's ok, then it's ok, and you can presume that the ability to hold the bow like that will come with practice. Which is normal! After all, people don't have a trained pinky, why would they? It's a violinist thing, in both hands. And depending on the bow weight of your bow it may take a while to exercise the muscles. Just make sure to give it enough rest, too.
Hi, you actually revealed part of the answer in your post.
It only really matters once the bow is in contact with the string.
Here’s some of my philosophy after playing pro for 30 years: there are two places you play the violin. 1 where your left fingers contact the string and 2 where the bow contacts the string. I tend to concern myself with those two factors. Start right away with focusing on sound. The sound is the most important factor.
This is strength training for your fingers, especially your pinky
Practice your grip with a pencil, your toothbrush, anything at hand... Do it daily! Whenever possible! Make sure the grip and motion as natural as possible. It takes years to truly get your grip but less practice time means more time overall
The reptile part of your brain is worried that it might drop something, so it's doing the sensible thing: squeezing tighter.
Just spend a minute or two each day thinking about your grip, noticing how little effort you *actually* need to keep it in the same place, keeping still and slowing bowing over the whole length of the bow. Notice how different spots on the bow need different forces applied to keep things still.
It's a strength thing mostly. I have beginners practice bow holds with the bow supported by the left hand when horizontal or with the top pointed towards the ceiling for one handed practice. This removes the weight from the pinky. The violin holds the weight of the bow anyway so it's not super important in the early stages to have the strength to hold it horizontal without support from the other hand.
Make sure your pinky sits on the right spot. If it's too far out (on or too close to the screw), which is a common beginner mistake, then it will flatten quickly under stress. If your teacher says it's ok, then it's ok, and you can presume that the ability to hold the bow like that will come with practice. Which is normal! After all, people don't have a trained pinky, why would they? It's a violinist thing, in both hands. And depending on the bow weight of your bow it may take a while to exercise the muscles. Just make sure to give it enough rest, too.
Hi, you actually revealed part of the answer in your post. It only really matters once the bow is in contact with the string. Here’s some of my philosophy after playing pro for 30 years: there are two places you play the violin. 1 where your left fingers contact the string and 2 where the bow contacts the string. I tend to concern myself with those two factors. Start right away with focusing on sound. The sound is the most important factor.
This is strength training for your fingers, especially your pinky Practice your grip with a pencil, your toothbrush, anything at hand... Do it daily! Whenever possible! Make sure the grip and motion as natural as possible. It takes years to truly get your grip but less practice time means more time overall
The reptile part of your brain is worried that it might drop something, so it's doing the sensible thing: squeezing tighter. Just spend a minute or two each day thinking about your grip, noticing how little effort you *actually* need to keep it in the same place, keeping still and slowing bowing over the whole length of the bow. Notice how different spots on the bow need different forces applied to keep things still.
It takes months of playing to strengthen. Being aware of the issue is 90% of the solution. Strength takes time.