NBA Coaching Changes 2014: Which team made the biggest improvement?

There were several teams that needed a new coach for the upcoming season. Which team made the biggest improvement?

Eastern Conference:

• Cleveland Cavaliers: Mike Brown --> David Blatt
• Detroit Pistons: Maurice Cheeks / John Loyer --> Stan Van Gundy
• New York Knicks: Mike Woodson --> Derek Fisher

Western Conference:

• Golden State Warriors: Mark Jackson --> Steve Kerr
• Los Angeles Lakers: Mike D'Antoni --> Vacant
• Minnesota TImberwolves: Rick Adelman --> Flip Saunders
• Utah Jazz: Tyrone Corbin --> Quin Snyder