The Kings will almost assuredly lose Samuel Dalembert to free agency, and Sacramento doesn't seem terribly to mind. But the team brought in Chuck Hayes to play both frontcourt positions (hopefully more power forward than center). Both are considered defenders first and foremost, but they do the work in different ways.
Dalembert is a shotblocker who swoops in to chase almost every shot taken around the rim. Some of those end up as blocks. Some, goaltending calls. But the work is primarily off the ball, covering for others' mistakes.
Hayes is more an on-ball defender, using his strength, smarts and relative length to make life uncomfortable for those he covers. He's not a shotblocker or someone who be able to erase guard penetration except those solid rotation and taking charges (two things he's adept at). If Dalembert is someone whose defensive impact comes in one zone -- around the rim -- Hayes is more a stopper who can follow an opposing star around and make life difficult.
Which one is more helpful? That's got to be something conditional on the rest of team. If your guards are slow-footed and your second big can't cover a pick-and-roll, you might need that shotblocker. But if your guards and second big are OK on fighting screens, perhaps having a shutdown big man is more useful on more possessions.
What do you think? Does the Hayes addition offset the Dalembert subtraction on defense?