Tweak to the Interest Formula

July 12, 2014

A minor problem with the interest formula

Log10[( N + 1 - R1) × ( N + 1 - R2 ) + 1 ]

{ 2 × max( R1, R2 ) - min( R1, R2 ) }
is that the maximum value (a #1 vs #1 matchup) depends upon the size of the field N. Since we're using it to assign games to one of the buckets
       int < 0.5
0.5 ≤ int < 1.5
1.5 ≤ int < 2.5
2.5 ≤ int < 3.5
3.5 ≤ int < 4.5
I'll normalize the value so that the maximum #1 vs #1 is 4.5. We do this by replacing the common (base 10) logarithm with the logarithm to base B

LogB[( N + 1 - R1) × ( N + 1 - R2 ) + 1 ]

{ 2 × max( R1, R2 ) - min( R1, R2 ) }

with

B = 4.5√( N2 + 1 ) = 9√{ ( N2 + 1)2 }

With 128 1A teams in 2014, B is about 8.64 and all of the interest values are about 7 per cent higher than those given by the old formula. Graphs of the game-interest based upon opponents' ranks for #25, #50, #75, #100 and #125 look like this: game interest vs opponents' ranks for selected team ranks

The revised list of "three star" interconference games is:

6-Sep #3 Michigan St at #7 Oregon B1G at P12
29-Nov #8 South Carolina at #11 Clemson SEC at ACC
30-Aug #1 Florida St vs #14 Oklahoma St (Arlington TX) ACC at B12
13-Sep #17 Central Florida at #4 Missouri AAC at SEC
30-Aug #22 Wisconsin vs #16 LSU (Houston TX) B1G vs SEC
29-Nov #24 Notre Dame at #21 Southern Cal ND at P12
22-Nov #18 Louisville at #24 Notre Dame ACC at ND
8-Nov #24 Notre Dame at #15 Arizona St ND at P12
30-Aug #11 Clemson at #23 Georgia ACC at SEC
4-Oct #6 Stanford at #24 Notre Dame P12 at ND
18-Oct #24 Notre Dame at #1 Florida St ND at ACC
20-Sep #34 Miami FL at #33 Nebraska ACC at B1G
13-Sep #13 UCLA vs #29 Texas (Arlington TX) P12 vs B12
18-Sep #2 Auburn at #27 Kansas St SEC at B12
6-Sep #35 Brigham Young at #29 Texas Ind at B12
13-Sep #33 Nebraska at #36 Fresno St B1G at MW

Four-star matchups are extremely rare. There are only 18 rank combinations with interest values greater than or equal to 3.5: #1 vs #s 1, 2, 3, or 4; #2 vs #s 2, 3, 4, or 5; #3 vs #s 3, 4 or 5; #4 vs #s 4, 5 or 6; #5 vs #s 5 or 6; #6 vs #6 and #7 vs #7. The only one scheduled for 2014 is November 29, #2 Auburn at #5 Alabama.

© Copyright 2014, Paul Kislanko