The PlayStation Move, like a Wii Remote bolstered by Motion Plus is supposed to tolerate people who stop pointing the controller at the TV. I accidentally completed a successful test of that yesterday.
I was trying Ubisoft's upcoming PlayStation 3 version of Racquet Sports, swinging through some tennis volleys with a company public relations person. If you have played real tennis or Wii Sports tennis, you will be able to accurately guess how the wand-shaped Move controller can be used to control your player's virtual tennis racket.
If you've played other Wii games, you may also know of the hazards of not pointing your controller in the direction of the Wii's sensor bar. Such bad aim is not a problem in Wii Sports, a game that does not rely on pointing control (just motion control). But if you have played a Wii shooter such as Metroid Prime 3: Corruption you will know that pointing the Remote outside the range of the Wii's sensor bar can confuse the hardware. Pointing a wandering Remote back at the TV usually corrects things, but the interruption of control can cause a game to go haywire, its camera spinning, your character broken from your control, and so on.
Until yesterday I hadn't tested the PS3's ability to track any wandering of its motion controller.
I was told by PlayStation Move creator Richard Marks when he showed me the controller a couple of months ago that the Move won't be so bedeviled by bad aim, should you aim a Move wand away from the PlayStation Eye, which serves as the "sensor bar" for the PS3. In the same way the MotionPlus catches wandering Remotes, Marks said the Move's other sensors could guess well enough as to the position of a wandering controller and allow for smooth, unbroken control.
Racquet Sports proved Marks correct. I'm not sure why the tennis game needed to use the Eye to track my movements. I don't know what it was looking for. But I know that the few times when I dropped my Move-holding hand, an alert box appeared on the screen, color-coded to the color of my Move's illuminated sphere-tip, telling me my controller was out of the camera's range. I raised my hand and the connection smoothly returned.
UPDATE: Several commenters below this post have inferred that the warning message I described above interrupted the flow of the game. That is incorrect. The warning message does not pause the game. The Move continues to be tracked even while the message appears, though I suspect, as Marks had told me, that the accuracy of the tracking would diminish the longer the controller is not within the PlayStation Eye's range. The small warning message that appeared in the corner of the TV was a helpful reminder for me to move my Move wand closer to the sensor range, but it did not obstruct my vision nor pause the game. The message appeared during shot replays, not during gameplay. I hope those clarifications help illustrate a clearer picture.