How?
Here are some numbers from
http://www.82games.com/0405SAS.HTM
DEFENSE:
effective FG% Allowed
player ON Court OFF Court Net
Duncan 43.8% 47.1% -3.3%
Nesterovic 43.8% 46.4% -2.6%
Ben Wallace 45.4% 47.6% -2.2%*
Bowen 45.2% 45.4% -0.3%
Parker 45.2% 45.3% -0.1%
Udrih 45.2% 45.3% -0.1%
Barry 45.4% 45.1% +0.3%
Nazr 46.3% 45.1% +1.2%
Brown 46.2% 44.8% +1.4%
Horry 46.4% 44.6% +1.9%
Ginobili 51.4% 46.7% +4.6%
Defensive rebounding
player ON Court OFF Court Net
Barry 72.8% 69.2% +3.6%
Duncan 71.9% 69.2% +2.8%
Parker 71.5% 69.0% +2.5%
Nesterovic 72.0% 69.7% +2.4%
Bowen 71.2% 69.9% +1.2%
Ben Wallace 70.8% 69.9% +0.9%*
Ginobili 70.8% 70.7% +0.2%
Brown 70.0% 71.1% -1.1%
Udrih 68.9% 71.5% -2.7%
Horry 68.2% 72.0% -3.8%
Nazr 65.3% 71.4% -6.2%
Defense: Pts per 100 Poss.
player ON Court OFF Court Net
Duncan 95.8 105.0 -9.1
Ginobili 97.1 103.5 -6.4
Nesterovic 96.8 102.5 -5.7
Ben Wallace 100.6 104.2 -3.5*
Bowen 99.4 100.9 -1.5
Parker 99.5 100.9 -1.4
Horry 99.9 99.9 -0.0
Udrih 100.9 99.5 +1.4
Barry 100.7 99.3 +1.5
Brown 103.4 98.3 +5.1
Nazr 109.4 98.8 +10.7
* I added DPOY just for comparison: Rasho is worth more in defense to spurs than big ben is to detroit.
as for his offensive "ineptness":
OFFENSE:
Effective FG%
player ON Court OFF Court Net
Duncan 51.5% 46.5% +5.0%
Ginobili 51.4% 46.7% +4.6%
Nesterovic 50.6% 48.2% +2.4%
Horry 50.2% 48.8% +1.3%
Parker 49.4% 49.0% +0.4%
Bowen 49.5% 48.8% +0.7%
Udrih 49.0% 49.4% -0.4%
Barry 48.7% 49.8% -1.1%
Brown 48.1% 49.8% -1.7%
Nazr 43.3% 50.1% -6.8%
Offensive Rebounding
player ON Court OFF Court Net
Nazr 36.6% 30.3% +6.3%
Ginobili 31.8% 30.2% +1.6%
Nesterovic 31.6% 30.7% +0.9%
Barry 31.5% 30.7% +0.7%
Udrih 31.5% 30.9% +0.6%
Duncan 31.1% 31.1% +0.0%
Parker 30.7% 31.8% -1.1%
Brown 29.8% 31.6% -1.8%
Bowen 30.1% 32.9% -2.8%
Horry 29.3% 32.0% -2.8%
Offense: Pts per 100 Poss.
player ON Court OFF Court Net
Ginobili 113.7 102.9 +10.8
Duncan 112.6 104.4 +8.2
Horry 110.8 107.9 +2.9
Nesterovic 109.9 108.1 +1.8
Parker 108.9 108.9 +0.1
Bowen 108.6 109.6 -1.0
Barry 108.0 109.6 -1.7
Udrih 108.7 109.0 -0.3
Brown 105.9 110.3 -4.4
Nazr 103.2 109.6 -6.4
Nesterovic is more of an impact on offense then for example parker...
In conclusion: It's not so much what Rasho does, it's what he does FOR THE TEAM.