+/- for the Iowa St. Game - Why does Jamari Play?

Game No. ------>     20            
Date:  1/25/2016
Opponent: Iowa St.
Location:  Ames (Hilton Coliseum)
                                 (+/-)                 x-(+/-)   
                                  per                   per     
Rnk  Player       Min   (+/-)     Min    x-Min  x(+/-)  x-Min     Δ  
***  **********  *****  *****    *****   *****  *****  ******   *****
  1  Mason III    33.1      -4    -0.12    6.9     -9    -1.31    1.19 
  2  Lucas        20.8      3     0.14    19.3    -16    -0.83    0.98 
  3  Diallo        4.2      2     0.48    35.8    -15    -0.42    0.90 
  4  Ellis        35.3      -8    -0.23    4.8     -5    -1.05    0.83 
  5  Mickelson     0.0      0     0.00    40.0    -13    -0.33    0.33 
  6  Manning       0.0      0     0.00    40.0    -13    -0.33    0.33 
  7  Self          0.0      0     0.00    40.0    -13    -0.33    0.33 
  8  Young         0.0      0     0.00    40.0    -13    -0.33    0.33 
  9  Greene       24.5     -10    -0.41   15.5     -3    -0.19    -0.21
 10  Graham       34.6     -13    -0.38    5.4     0     0.00     -0.38
 11  Vick          1.1      -1    -0.88   38.9    -12    -0.31    -0.57
 12  Mykhailiuk    1.1      -1    -0.88   38.9    -12    -0.31    -0.57
 13  Bragg Jr.     6.1      -5    -0.82   33.9     -8    -0.24    -0.58
 14  Selden Jr.   29.9     -16    -0.54   10.1     3     0.30     -0.83
 15  Traylor       9.4     -12    -1.28   30.6     -1    -0.03    -1.25
                
2016 Season Total                    
Through  20  Games                
                                 (+/-)                 x-(+/-)   
                                  per                   per     
Rnk  Player       Min   (+/-)     Min    x-Min  x(+/-)  x-Min     Δ  
***  **********  *****  *****    *****   *****  *****  ******  *****
  1  Ellis         599    249     0.42     216    40     0.19     0.23 
  2  Selden Jr.    584    229     0.39     231    60     0.26     0.13 
  3  Mason III     657    230     0.35     158    59     0.37     -0.02
  4  Graham        630    176     0.28     185   113     0.61     -0.33
  5  Mykhailiuk    248    134     0.54     567   155     0.27     0.27 
  6  Mickelson     164    116     0.71     651   173     0.27     0.44 
  7  Bragg Jr.     210     94     0.45     605   195     0.32     0.13 
  8  Lucas         255     83     0.33     561   206     0.37     -0.04
  9  Greene        214     74     0.35     601   215     0.36     -0.01
 10  Traylor       250     22     0.09     565   267     0.47     -0.38
 11  Diallo        131     43     0.33     684   246     0.36     -0.03
 12  Vick           68     12     0.18     747   277     0.37     -0.20
 13  Manning        25      -3    -0.12    790   292     0.37     -0.49
 14  Young          18      -7    -0.39    797   296     0.37     -0.76
 15  Self           23      -7    -0.31    792   296     0.37     -0.68