There are several possible signs that your piano is a candidate for regulation. These include:
Lack of sensitivity
Decreased dynamic range
Keys out of level
Inability to play softly with control
A sluggish action or deep grooves in the hammers indicate the need for reconditioning or repair. Ask your technicians to show you what needs adjustment on your piano.
No amount of practice can compensate for a poorly maintained action. Poor legato touch, chord playing where all notes of the chord don't speak clearly, a gradual loss of subtlety in phrasing, and an inability to execute quick passages or note repetitions evenly may be the fault of the piano -- not the player.
Get detail info: Grand Piano Regulation