Use this as your Points for Playing formula:
if(n <= 7, switch(r, 1, 18, 2, 11, 3, 6, 4, 3, 5, 2, 6, -3, -6))
+ if(n == 8, switch(r, 1, 20, 2, 13, 3, 8, 4, 5, 5, 2, 6, 0, 7, -3, -6))
+ if(n == 9, switch(r, 1, 23, 2, 15, 3, 9, 4, 6, 5, 3, 6, 1, 7, 0, 8, -3, -6))
+ if(n == 10, switch(r, 1, 26, 2, 17, 3, 10, 4, 7, 5, 4, 6, 2, 7, 1, 8, 0, 9, -3, -6))
+ if(n == 11, switch(r, 1, 29, 2, 19, 3, 12, 4, 8, 5, 5, 6, 3, 7, 2, 8, 0, 9, 0, 10, -3, -6))
+ if(n == 12, switch(r, 1, 32, 2, 21, 3, 14, 4, 9, 5, 6, 6, 4, 7, 2, 8, 1, 9, 0, 10, 0, 11, -3, -6))
+ if(n == 13, switch(r, 1, 36, 2, 24, 3, 15, 4, 10, 5, 7, 6, 5, 7, 3, 8, 2, 9, 0, 10, 0, 11, -1, 12, -3, -6))
+ if(n == 14, switch(r, 1, 40, 2, 26, 3, 17, 4, 12, 5, 8, 6, 6, 7, 4, 8, 3, 9, 0, 10, 0, 11, 0, 12, -1, 13, -3, -6))
+ if(n == 15, switch(r, 1, 44, 2, 29, 3, 19, 4, 14, 5, 10, 6, 7, 7, 5, 8, 3, 9, 0, 10, 0, 11, 0, 12, -1, 13, -1, 14, -3, -6))
+ if(n == 16, switch(r, 1, 48, 2, 32, 3, 21, 4, 16, 5, 11, 6, 8, 7, 6, 8, 4, 9, 1, 10, 0, 11, 0, 12, -1, 13, -1, 14, -1, 15, -3, -6))
+ if(n >= 17, switch(r, 1, 51, 2, 35, 3, 23, 4, 18, 5, 13, 6, 10, 7, 7, 8, 5, 9, 2, 10, 0, 11, 0, 12, -1, 13, -1, 14, -1, 15, -2, 16, -3, -6))
Big and ugly, but will work. Two things to note: The first and last if() statements use <= (less than or equal to) and >= (greater than or equal to), so the formula will still work if you have fewer than 7 players or more than 17. And the final value in each switch statement does not have a qualifying rank, which means it's an "else" clause, so any ranks not qualified in the switch statement will receive -6 points. This only matters for the final if() statement. In other words, if you have 25 players, ranks 17 through 25 will receive -6 points.