"But moving just the forefinger — not the whole hand, or bunching all the fingers, but just the forefinger — actually makes the mouse rotate, particularly for left- and rightward movements. If the sensor is up the front of the mouse, that rotation of the mouse will give the user the desired outcome: the cursor will accurately move to the left or right, or back and forth. But if the sensor is in the middle of the mouse, then all of that fine control is lost: no or little movement will be registered."

Paraphrased: With the ball/sensor at the top of the mouse, you can have more horizontal control by rotating the mouse left or right.

My response: With the way that the hand rotates (the base of the hand as a fixed point), the speed of the cursor slows down the farther back the sensor is placed. So in essence, you can get more precise horizontal control with our current sensor placement standard than with a index-thumb sensor.

This is good because it's easier for the human arm to move the mouse quickly horizontally by rotating at the elbow than it is to move vertically (by rotating the shoulder, or in my case, moving my wrist/fingers).

Then again, I have my mouse set pretty sensitively, so I can traverse the entire screen within the range motion my wrist allows (no need to lift my hand at all). Also, I'm pretty sure that the difference is negligible compared to sensitivity settings and advances in technology (such as slowing the cursor when the mouse is moved slower... that sounds obvious, how about decreasing the absolute speed of the cursor when the mouse is moved slower).

My first thought was that putting the sensor/ball in the middle means the mouse is less sensitive to the way in which you hold it. That would mean that if you hold the mouse at a slight angle, it would still behave the same as if you hold it straight on. If you put the sensor in the front, the mouse becomes more sensitive to its orientation, but it limits the different ways in which you can hold the mouse since you must hold it straight on for it to behave the same.

It only becomes sensitive to its orientation during the process of changing the angle of the mouse and only then if you rotate the mouse about the dead center. For yourself I'd imagine that you only really re-orientate the mouse once per use. Also I'd imagine that you'd quickly start rotating the mouse about the position of the sensor if it was a problem.

Anyone still using their wrist, elbow or should to move the mouse is asking for repetitive stress injuries. I highly recommend you try a trackball. Using your fingers to move the cursor is a lot more convenient, the mouse itself stays in the exact same place relative to the keyboard making it easier to switch between them, and takes up less room on your workspace, as it doesn't need room to move around.

well, I think that nowadays the optical sensors are quite sensitive, and it's not that hard to achieve any apparent placement of the sensor through some software modification of the output. So even if you place your mouse at the far back, you can make it behave as though it's in front. Or at least I think so...

well, I think that nowadays the optical sensors are quite sensitive, and it's not that hard to achieve any apparent placement of the sensor through some software modification of the output. So even if you place your mouse at the far back, you can make it behave as though it's in front. Or at least I think so...

I don't see how. I presume mice only register changes in position, and not changes in orientation. That's all you can measure with a ball so I presume that's all that is measured with optical mice. So if you were for instance to hold the top of the mouse in place and rotate the rest of the mouse around that point, you would definitely register a change in position with the optical sensor, and I don't know how you would do this in software. So the mouse won't ever behave exactly like it would if the sensor were at the front.

I think that your assumption is incorrect. The optical sensors are comparing images, currently looking for translation. There's not reason they couldn't look for rotation.

However, it is a firmware, rather than software change.

I don't see how that works. If the wire came out of the back it would be in the way of my wrist.

I don't see how it would have anything to do with the home keys.

Edit: Wait. Do you put the mouse in front of the keyboard? I put mine to the side. I think most people put it to the side.

I'm really confused by your question. I'm really curious how you position your mouse relative to the keyboard.