According to physics, a true "check" on a swing is an object attached to non-resilient medium...like a weight-on-a-string. You need to CREATE centrifugal force in order to move the object on such a device.  If you fail to do so, by attempting to employ a different type of force other than centrifugal--like a levering force, the object will simply not move.  It must necessarily be SWUNG in order to move !

The putting stroke, and indeed the golf swing at large are no different.  It is essentially, as Bobby Jones asserted, "a weight attached to the hands by an imponderable medium, to which a string is a close approximation."  The surest way to get the clubhead moving in the most efficient, effective, consistent, accurate, and powerful manner is to wield it the manner in which one would swing a weight on a string.  

The String Theory Putter training aid is the only training device on the market that takes this concept of a perfect "check" on a swing and allows the user to strike a real golf ball in the form of a putt during practice.  It is the surest, most effective way of translating that ineffable feel that Bobby Jones talked about into tangible, permanent, results for your putting and golf game.