An open bridge works OK with draw shots most of the time because the shot itself forces the shaft down into the bridge. When adding side the open bridge may show some flaw, the stick starting to move sideways before the tip has left the cue ball. This can cause more side than expected, can cause miscues too if the shot was already planned with the tip out towards the edge of the maximum side possible. One thing about the open bridge, you are dropping the shaft into a "V" shape. Where exactly is that "V" pointing? Are both sides of the "V" equally strong and stiff with the same amount of give?
A closed bridge can give some level of 360 degree support so no matter where the tip hits the cueball it is better restrained from moving further out on the cue ball. Shooting follow it is obvious that a closed bridge has better control.
The advantages of an open bridge are two-fold. One, it is generally more comfortable. The other thing is that you get a longer unobstructed view of the shaft to aim with. This is of somewhat dubious value for most shots because those shooting with a closed bridge learn to aim with what they can see. It might even be argued that the finger wrapped over the shaft breaks it up into two areas to aim with, more like front and rear sights on a gun.
The only person that played above "C" level and mentored me a little was an old shortstop that owned a hall. He advocated always using a closed bridge and always using a short bridge. Try this one night when you can't make a ball in the ocean and you may be surprised. It has turned around more than a few bad nights for me.
Respecting my mentor, I went to all closed bridge. However I found a small percentage of shots I did need an open bridge to see. I was shooting 10%-15% open bridge and the rest closed. After six or eight months I was shooting roughly 25% open bridge because it was more comfortable and easier. I could also see my tip at cue ball address on all shots. However, I have never been convinced that an open bridge is as sound as a closed bridge. Speaking of bridges, I can find thousands of closed joints around pins on road bridges that use them. I will be hard pressed to find one pin just laying in a V groove. If such a thing exists, I will bet that the pin and groove are perfectly aligned, unlike a typical pool open bridge which relies on the grip to keep the shaft aligned.
Carom has came into the conversation. Carom uses a closed bridge because the balls are roughly a half ounce heavier and are hit with more spin. To put it in simple terms, the bridge has more side load on it playing caroms than it has playing pool.
Here is Willie Hoppe. At a little past 2:48 his bridge is very clearly shown and explained. Closed bridge tight enough the loose meat of the fingers moves back and forth. At about the three minute mark it is emphasized to stroke from the shoulder, not the elbow. Those that have suffered through fifteen years or so of my posts know I have commented many times that the stroke from the shoulder seems to make better sense from a mechanical and human behavioral standpoint. We swing our arms from the shoulder many times during any typical day. How often do we swing our arms from the elbows in daily activity? I think it is generally accepted that big joints making tiny movements are easier to control than tiny joints making relatively big movements in most or all forms of competition, except maybe some cue sports.
We tend to think of current methods as the most advanced but that isn't always true. The pendulum is easy to teach, easy to troubleshoot. However, I would bet that it disappears in time. Likewise the stance with one locked knee, or any locked knee configuration to be clear. Simpler often means best, not always though.
Watch Mr Hoppe. Who is there in pool today that has better cue ball control than Mr Hoppe? Freely moving shoulder, closed bridge, carom and billiard championships by the dozen!
Hu