Matthew:
"Snugness" is not a substitute for "proper construction." One of the issues with the closed bridge, is where the wood of the cue shaft is touching skin -- and where on the hand/fingers that skin is. If the cue shaft is touching a very fleshy part of the hand/fingers (e.g. the flesh between the joints on the fingers, or the webbing between the thumb and the hand), there is the issue of that flesh "wobbling" while the shaft rides upon it. This is a common problem with the "merely loop the index finger over the thumb, press the index finger's tip upon the thumb tip" type of closed bridge. (I.e. the closed bridge "of old.") As you might guess, any inconsistency here in the bridge hand, will introduce an error in where you hit the cue ball -- anywhere from 1/8 to 1/4 inch! (That's nevermind the new change in the cue's angle from where you originally "intended" to hit the cue ball.) Merely applying pressure (tightness/firmness) to the bridge will probably solve some of the "wobbly flesh" issues, but not all of them. (The flesh moving back and forth problem is still there because of friction; it's just that now you've removed some of the "slack" and the resulting space in the bridge for the cue's direction to astray.)
I dare say most players today use a different type of closed bridge, which is the "index finger pressing down upon the middle finger" style of closed bridge that you say (above) you viewed in my pics. This style of closed bridge positions very bony parts of the fingers against the cue shaft's wood surface, so that the issue of "wobbly flesh" is minimized. Basically, you have a hard surface meeting a hard surface, and it's much more stable / predictable.
However, because there's now an inherent "V" channel in this style of bridge (that isn't there with the old-school "index finger looped over tip of thumb" closed bridge -- which is more of an "O" aperture). You have to orient that "V" channel correctly, otherwise the taper of your cue shaft will introduce a bit of "rise" as the cue shaft's girth gets thicker and thicker as it rides through that "V" channel. If the "V" channel is lying on its side like this ">" (for a right-handed/lefthand-bridge player), or like this "<" (for a left-handed/righthand-bridge player), the "rise" occurs from left-to-right or right-to-left as the cue rides through that flopped-over "V" channel. Thus, you have the centerline of the cue moving from side to side as it rides through that flopped-over "V" channel.
That's why you'll see many pros that will use this type of bridge WITHOUT resting the palm of the bridge on the table surface -- they're just pressing down on the middle/ring/pinkie fingertips (or even just the middle/pinkie, with the ring finger "tapping" the table surface, or just tucked under the palm of the hand). Or, as Alex Pagulayan does, you'll see him scrunch the index finger's pressure point further up onto the middle finger -- towards or even on top of the second joint -- to tilt that "V" channel upwards and try to "right" it straight up and down.
It might seem like a lot of work, and those that use an open bridge -- where the upright "V" channel naturally occurs -- may say, "look at all that crap you have to do with the closed bridge -- why even bother?" But the stability that a proper closed bridge offers over an open bridge is a boon to your play. And the first time you do it correctly, you'll have that "light bulb illuminated over your head" moment -- that "Aha!" moment. And your game just notched up another level.
Hope this is helpful,
-Sean
