See Strength of Schedule for an explanation. There are three sos calculations:
the 1st averages the opponents computer rating based on
 computer margin of victory "Reg In" and "ROM", the 2nd
 is similar to the first but instead of a simple average, it
 weighs games against stronger teams more heavily, and
 the 3rd is based on the RPI SOS formula used by the NCAA. This factor is not used in the power rating calculation.
          
      
   
     
   
           
           

Use the Report Scores link for both scores and missing games.
     
  
  
   
Rank Team                    Total  SOS Ave   SOS Wt Ave  SOS RPI    W  L  T
                             Games Rnk Value  Rnk Value  Rnk Value
 
   1 Lakeside School           14   1  67.44   2  38.74   1   0.54   9  3  2
   2 Seattle Prep School       12   2  67.36   1  38.82   4   0.52   5  7  0
   3 Issaquah                  13   3  67.29   3  38.61   2   0.52   7  5  1
   4 Bellevue                  11   4  67.23   4  38.09  11   0.49   0 11  0
   5 Holy Names Acad, WA       11   5  67.04   6  37.92  10   0.49   1 10  0
   6 Eastside CS, WA           12   6  66.90   5  37.96   6   0.50   5  7  0
   7 Roosevelt, WA             11   7  66.75   7  37.62   9   0.49   2  9  0
   8 Tacoma                    11   8  66.34   8  37.16  12   0.49   4  7  0
   9 Mercer Island             12   9  66.27   9  37.05   7   0.50   6  5  1
  10 Lake Sammamish            12  10  65.74  10  36.27   8   0.49   7  4  1
  11 Bainbridge Island         14  11  65.41  11  35.43   3   0.52  14  0  0
  12 Snohomish                 18  12  65.33  12  35.40   5   0.50  14  3  1