The first year members were UC, Butler, Western Reserve and Ohio. In 1948 the above four members were joined by Western Michigan and Miami. Kent joins in 1951 and BG and Toledo in 1952 which marks the year that the six oldest members have been in the league. If we are counting total wins, that is the first year that would be most logical. Here are the win totals for those six between 1952 - 1961.
Miami 38
Ohio 36
BG 32
Kent 31 Kent was a decent program until about 1961.
WMU 16
UT 15
So taking into account those years with all the same six, total wins are:
Toledo 443
Miami 431
BG 411
WMU 380
Ohio 360
Kent 257 Kent jumps ahead of Northern Illinois by 12 wins but NIU has been in the league 35 less years overall.
If one counts inclusive of the 1947-51 years the Miami leads the conference in all time wins with 445 to Toledo 443. Miami has the most MAC championships 17, BG and Toledo tied at 12, CMU 7, NIU 6, OU 5, Ball St 4, Western 2, EMU, Kent, Buffalo and Akron 1 each.