Staccato in Piano Playing

1. Staccatissimo is obtained by allowing the key to spring up the instant that its journey downwards is completed.
   The damper being thus allowed to reach the strings, the sound is instantly checked.
2. Clearly, you cannot make or compel a key to rise.
   You can only allow the key instantly to rise upon tone-production, thus permitting the damper instantly to reach the string.
   Note:To obtain Staccatissimo, the effort of tone-production and its subsequent immediate cessation must be so accurately timed that the key may rebound instantly.
   Anything less short than staccatissimo is therefore always in the nature of a Tenuto. This tenuto may last any degree up to the full extent of the written note. You may even allow the tone to last longer than its written value, and may thus overlap it into the next sound, when desirable; thus creating a Legatissimo or super-legato.
3. If you mis-apply or inaccurately time the force with which you intend to produce a tone, and thus, instead of producing key-motion (and string-speed) allow the force to be wasted on the beds under the keys, then your tone cannot correspond with your musically-intended wish, and the effect will be unmusical in proportion to your misjudgment of the exact requirements of the key.

Tobias Matthay's Definition of Keybedding