Create 2 teams at random based on win percentage

Option Explicit


Sub MakeTeams()
Dim Players(200, 3), TeamSize(10) As Integer, TeamRating(10) As Double
Dim i As Integer, r As Integer, j As Integer, c As Integer, ctr As Integer
Dim Numplayers As Integer, NumTeams As Integer, trials As Integer
Dim t As Integer, tc As Integer, MaxRating As Double, MinRating As Double
Dim MyText As String
' Written by Eric W.  1/9/2016
Application.ScreenUpdating = False
Sheets("Sheet1").Range("I2:AK16").Value = ""
' How many teams?
    NumTeams = Range("D2").Value
    If NumTeams > 10 Or NumTeams < 2 Or Int(NumTeams) <> NumTeams Then
        MsgBox "The number of teams must be an integer from 2-10."
        Exit Sub
    End If


' Read all the players and ratings
    r = 2
    Erase Players, TeamSize, TeamRating


    While Cells(r, "A") <> ""
        If r > 201 Then
            MsgBox "The number of players must be under 200."
            Exit Sub
        End If
        Players(r - 1, 1) = Cells(r, "A")
        Players(r - 1, 2) = Cells(r, "B")
        r = r + 1
    Wend
    Numplayers = r - 2


' Figure out the team sizes
    For r = 1 To NumTeams
        TeamSize(r) = Int(Numplayers / NumTeams) + IIf(r <= (Numplayers Mod NumTeams), 1, 0)
    Next r


' Make random teams
    trials = 0
    While trials < 100
        Call Shuffle(Players, Numplayers)


' Figure out the team ratings
        t = 1
        tc = 1
        Erase TeamRating
        MaxRating = -1
        MinRating = 11
        For i = 1 To Numplayers
            TeamRating(t) = TeamRating(t) + Players(i, 2)
            tc = tc + 1
            If tc > TeamSize(t) Then
                TeamRating(t) = TeamRating(t) / TeamSize(t)
                If TeamRating(t) > MaxRating Then MaxRating = TeamRating(t)
                If TeamRating(t) < MinRating Then MinRating = TeamRating(t)
                t = t + 1
                tc = 1
            End If
        Next i


' Max team rating - min team rating within the limit?
        If MaxRating - MinRating <= Cells(2, "F") Then GoTo PrintTeams


' Nope, try again
        trials = trials + 1
    Wend


    MyText = "Unable to find a valid set of teams in 100 tries." & Chr(10) & Chr(10)
    MyText = MyText & "You may try again using a higher MaxRatingDiff or" & Chr(10)
    MyText = MyText & "add more players to list or decrease the NumTeams"
    MsgBox MyText
    Exit Sub


' Print the teams
PrintTeams:
    Range("J1:AP20").ClearContents
    ctr = 1
    For i = 1 To NumTeams
        c = i * 3 + 6
        Cells(1, c) = "Team " & Chr(64 + i)
        For j = 1 To TeamSize(i)
            Cells(j + 1, c) = Players(ctr, 1)
            Cells(j + 1, c + 1) = Players(ctr, 2)
            ctr = ctr + 1
        Next j
        Cells(TeamSize(1) + 3, c + 1) = TeamRating(i)
    Next i
Application.ScreenUpdating = True
End Sub
' This team will randomly shuffle the players
' (It's really a bad sort, but with under 100 players, it should be good enough.)
Sub Shuffle(ByRef Players, ByVal Numplayers)
Dim i As Integer
Dim j As Integer
Dim a, b, c
' Assign a random number to each player
    For i = 1 To Numplayers
        Players(i, 3) = Rnd()
    Next i


' Now sort by the random numbers
    For i = 1 To Numplayers
        For j = 1 To Numplayers
            If Players(i, 3) > Players(j, 3) Then
                a = Players(i, 1)
                b = Players(i, 2)
                c = Players(i, 3)
                Players(i, 1) = Players(j, 1)
                Players(i, 2) = Players(j, 2)
                Players(i, 3) = Players(j, 3)
                Players(j, 1) = a
                Players(j, 2) = b
                Players(j, 3) = c
            End If
        Next j
    Next i


End Sub