ChicagoRJ:
Allison is a big underdog against even the 2nd tier of male pros. Her main weakness is lack of a power stroke (a product of having no elbow drop? possibly).
Everyone:
I would equate having no elbow drop to skiing with a wedge. In skiing, all beginners start learning to ski with a wedge because they wouldn't be able to get anywhere if they tried to ski parallel right off the bat. But once they get more comfortable with skiing, they gradually move to skiing parallel, which is more natural and takes less effort. Its basically a walk before you can run situation
How many A players or better have you seen in person with no elbow drop? I could probably count the number I have seen on one hand.
Obviously the easiest way (not necessarily the best) to attain mechanical consistency is to make the fewest body motions possible aka pendulum stroke. This is good for beginners because it gives them a starting point, something they can do with consistency, before venturing out into the real pool world. The down side is that there is wasted energy in the pendulum stroke and it is difficult to produce at high velocities. Let me explain.
Newton's first law is that an object in motion tends to stay in motion unless acted on by another force. If your cue is going straight, it naturally wants to go straight unless you do something to it.
Lets focus on a pure centerball hit for moment because draw, follow, and english and such complicate things somewhat. After a pendulum stroke, your cue's butt is higher and the tip is lower than the original positions. meaning it didn't go straight (vertically). This is evidence that the cue was acted on by other forces (your arm) during the stroke and was made to go through unneccessay changes in momentum. In a pendulum stroke, you push through the cue ball and then inevitably pull up (on the back of the cue, the tip goes down as a result of the lever that is your stroke hand, bridge hand, or a combination of both). In an elbow drop stroke, you just push the cue through the cueball.
Why is this important? Even if the pulling up (on the back of the cue) in the pendulum is completely after the cue ball is gone, it still means you are focused on pulling up, where as you should be focused on making the cue go straight. It also leads me to conclude that you are exerting effort where it need not go.
This wasted effort has several side effects: 1) Your body is making motions that have no impact at all on the cueball. 2) Your cue is not following the path that it naturally wants to go. 3) It means you are focusing on doing somthing that is not necessary. Lets go over these points one by one.
1) Lets say we have a robot modeled after a human arm and it only had to make 1 long straight in shot with 1 set bridge length at 1 set elevation. In this case, it would indeed be easier to design the robot to only do a pendulum stroke and the robot would hit the cueball when its arm was perfectly perpendicular at the exact height intended on the cueball. This is because the robot will hit the cueball the same way regardless of speed.
Unfortunately for us humans, we have bodies that must compensate grip pressure, muscle flex, wrist movement, elastic skin on our grip hands, etc. in order to achieve higher cue speeds. Sure, I can bunt a ball with a perfect pendulum stroke, but there is no way I can get the cue moving at 10+mph with exactly the same mechanics as a bunt. Trying to reproduce that same stroke regardless of speed is futile and wasted effort.
A good example is the Austrailian Oyster's reply to Mike Massey's extreme draw vid. Massey does the shot with an elbow drop and has very nice fluidity and timing. It looks almost natural. I figure even I could get it down after a few tries. The Austrailian Oyster on the other hand does the shot with a "text book perfect" pendulum stroke, no elbow drop what-so-ever. It is one of the most forced, robotic, and ugly power strokes that I have ever seen. Baring weight training, there is no way I could reproduce that stroke. I would go as far to surmise that the Austrailian Oyster even with his so called "perfect pendulum stroke" took more than a few takes on that video and the missed attempts were probably not so pretty. Not to mention he was using a low deflection shaft, which is generally easier to deliver than a standard shaft. Mike doesn't strike me as the type to use a low deflection shaft, although I could be wrong.
2) Lets go back to Mr. Robot. He makes that one long straight in with extreme accuracy, provided it is set up perfectly every time. Unfortunately, variations in bridge length, bridge height, elevation, etc. will prevent him from playing good pool even if you handed Efren himself the controls. Once the cueball gets anywhere near a rail or a ball impedes his bridgehand, its game over for Mr. Robot.
For us humans, who have to deal with even more variations than that, such as lack of metal joints, not being able to grip the exact same spot on the cue every time, having a bridge hand that flexes (even if only very slightly), how is it possible that we can be expected to deliver a cue more accurately to a target that is maybe a square milimeter in width on the cueball when we are making the cue move not only forward, but vertically as well?
Lets say there are two types of consistency, mechanical consistency and cueing consistency. Mechanical consistency is the consistency of the body; how consistent your body is moving, generally the less movement, the better if you want mechanical consistency. Cueing consistency is the consistency of the cuel; how accurately your cue strikes the cueball.
Let me make things simple, mechanical efficiency does not necessarily equate to cueing consistency.
A pendulum stroke means that you only have 1 point in your stroke where the cue strikes precisely where you wanted it to because the tip is moving up and down on the vertical axis. A vertically and horizontally straight stroke, provided it is indeed vertically and horizontally straight has the whole of the stroke length to strike the cue ball where you wanted.
Lets create a thought experiment. We have 2 robots, one delivers the cue like an arrow, basically perfectly parallel to the table. The other delivers the cue in a pendulum stroke, the tip starts from the bridge hand and finishes down on the table. Lets forget about the fact that both of the robots would have trouble bridging over rails and over balls. Next, lets assume you have to position the robots into shots yourself. Which would you rather use, the robot that delivers the cue to the same spot regardless of bridge length, or the one that you have to position at precisely the correct bridge length or else it hits the cueball too low or too high?
Elbow dropping has a purpose, it is to allow the momentum of the cue to travel in the same direction as it was going from the beginning of the stroke. Basically our goal is to let the cue go in as natural a direction as possible. Now a perfectly horizontally and vertically straight stroke is impossible as we are only human, our back stroke naturally raised the back end of the cue (unless you put 2 elbow drops and an elbow raise in your stroke), and the rails tend to disallow for it, but to purposfully not have a vertically straight stroke and put effort into making your stroke not straight is a waste of time.
Now if you naturally have a pendulum stroke and can't get the timing of a straighter stroke down, thats a problem you have to work out with practice or a factor you will have figure out some way to overcome.
3) This one is self explanatory, why focus on doing something that is unnatural and not necessarily better for you?
Lets sum things up.
At slow speeds, provided you set yourself up correctly, there is no real difference between the two strokes unless you are horrible at timing. A person with a horizontally crooked elbow drop stroke will most likely have a crooked pendulum stroke unless he has never held a cue before. At high speeds, the difference is that the elbow drop is not as affected by slight variations in your body, setting, etc. because you have more than 1 point to hit the cue ball precisely where you intended. Also at high speeds, the body isn't wasting effort trying to force the cue on a path it doesn't want to go naturally.
But who knows really, maybe there was a scientific study on people's arms and it figured out that you can be X% more consistent with a pendulum stroke. Even IF that is true, there is no doubt that the elbow drop can be delivered consistently enough for nearly every top pro. Meaning that once you get to a certain level, the one advantage a pendulum stroke might have had is negated. This level is lower than you might think because A players tend to have very consistant strokes. The argument "well do you have as good timing as earl, or X world class player" is thus irrelevant. Add in the fact that the elbow drop allows you to hit more accurately at high speeds. I see no reason at all to develop a pendulum stroke past the "picked up a cue for the first time" stage.
Even if that hypothetical study mentioned earlier was true, you are still sacrificing power for consistency.
In high level pool, stroke is EVERYTHING. If you sacrifice power for consitency you will get beat by the guy who has power and consistency.