Suns forward Markieff Morris is having a breakout season in Phoenix after a couple of so-so years in the NBA. Actually, the former Jayhawk is playing so much better that he leads the league in PER improvement ahead of teammate Gerald Green and Kings center DeMarcus Cousins, who's totally living up to the max contract he signed last September.

Former Sun Jared Dudley and mercurial Knick JR Smith are right at the end of the list with their PER going down drastically this season.

Full data below.

* All data from Basketball-Reference.com

BIGGEST IMPROVEMENT

PLAYERS TEAMS 2013-14 PER 2012-13 PER PER CHANGE
1. Markieff Morris Phoenix 18.5 12.6 +5.9
2. Gerald Green Phoenix 15.8 9.8 +5.9
3. DeMarcus Cousins Sacramento 25.8 20.2 +5.6
4. Anthony Davis New Orleans 27.2 21.7 +5.5
5. Draymond Green Golden State 12.4 7.1 +5.3
6. Austin Rivers New Orleans 11.1 5.9 +5.2
7. Marco Belinelli San Antonio 15.5 10.4 +5.1
8. Brandon Knight Milwaukee 16.9 12.0 +4.9
9. Goran Dragic Phoenix 22.0 17.5 +4.5
10. DeMar DeRozan Toronto 18.5 14.7 +3.8
11. Paul George Indiana 20.5 16.8 +3.7
12. Arron Afflalo Orlando 16.7 13.0 +3.7
13. Marcus Morris Phoenix 15.0 11.3 +3.7
14. Lance Stephenson Indiana 15.3 11.8 +3.5
15. Rudy Gay Sacramento 18.9 15.6 +3.3
16. Isaiah Thomas Sacramento 20.7 17.5 +3.2
17. Bismack Biyombo Charlotte 13.2 10.1 +3.1
18. Courtney Lee Memphis 14.7 11.7 +3.0
19. Jodie Meeks LA Lakers 14.4 11.4 +3.0
20. Boris Diaw San Antonio 14.8 11.9 +2.9
21. Kyle Lowry Toronto 20.3 17.5 +2.8
22. Damian Lillard Portland 19.0 16.4 +2.6
23. Dwight Howard Houston 21.6 19.4 +2.2
24. Kevin Durant Oklahoma City 30.5 28.3 +2.2
25. Brandon Bass Boston 14.5 12.30 +2.2

BIGGEST REGRESSION

PLAYERS TEAMS 2013-14 PER 2012-13 PER PER CHANGE
1. Jared Dudley LA Clippers 8.9 14.9 -6.0
2. JR Smith New York 12.4 17.6 -5.2
3. Andrew Nicholson Orlando 10.2 15.1 -4.9
4. Shawn Marion Dallas 13.9 18.0 -4.1
5. Luis Scola Indiana 12.9 16.7 -3.8
6. Jason Thompson Sacramento 10.8 14.6 -3.8
7. Tayshaun Prince Memphis 7.9 11.5 -3.6
8. Josh Smith Detroit 14.2 17.7 -3.5
9. Corey Brewer Minnesota 11.2 14.7 -3.5
10. Jose Calderon Dallas 15.4 18.8 -3.4
11. JJ Hickson Denver 16.4 19.7 -3.3
12. Tony Parker San Antonio 19.7 23.0 -3.3
13. Tim Duncan San Antonio 21.1 24.4 -3.3
14. Carlos Boozer Chicago 13.9 17.1 -3.2
15. Greivis Vasquez Toronto 13.3 16.3 -3.0
16. Andray Blatche Brooklyn 18.9 21.9 -3.0
17. Paul Pierce Brooklyn 16.2 19.1 -2.9
18. Gerald Henderson Charlotte 13.5 16.4 -2.9
19. John Salmons Toronto 7.5 10.2 -2.7
20. George Hill Indiana 14.0 16.6 -2.6
21. LeBron James Miami 29.0 31.6 -2.6
22. David West Indiana 17.6 20.1 -2.5
23. Derrick Williams Sacramento 12.1 14.5 -2.4
24. Roy Hibbert Indiana 14.9 17.3 -2.4
25. Enes Kanter Utah 15.3 17.6 -2.3

* Only players with a minimum of 20 games played and at least 12 minutes per game on average in both 2012-13 and 2013-14 are listed.