Interesting topic; one that could apply to all sports in all seasons in which the 'Dores were not undefeated.
I nominate the 1974 Men's Basketball loss at the end of the season to a mediocre Florida team that finished 9-9 in SEC play. Vanderbilt had swept mighty Alabama (with Douglas, Dunn, Odums, Cleveland, Russell coached by C.M. Newton) and only needed to beat Florida for the outright SEC title.
The loss left Vanderbilt and Alabama with identical 15-3 SEC records, but
the head-to-head tiebreaker sent Vanderbilt to the NCAA Tournament Southeast Regional in Tuscaloosa. Alabama fans had bought most of the tickets, expecting the Tide to be in the regional. Needless to say, tickets were plentiful and cheap after the first round.
Poor Alabama, despite a 22-4 record and an AP #14 ranking, stayed home. The N.I.T. would have been an option in other years (although equally good VU teams had been passed up by that "prestigious" tournament) and there was a new "Conference Commissioners Tournament" for second place teams. But the NCAA had a rule that if a university was hosting an NCAA game and its own team did not qualify that team could not play in another tournament.
On a related note, here are some Vanderbilt non-SEC Champs teams that
did not make the National Invitation Tournament. LINK to Sports-Reference.com web pageSEASON .... COACH ......... W-L ...... Final AP
1954-55 ... Bob Polk ..... 16-6 ......... 17 *
1955-56 ... Bob Polk ..... 19-4 ......... 12 *
1956-57 ... Bob Polk ..... 17-5 .......... 8 *
1960-61 ... Bob Polk ..... 19-5 ......... -- **
1963-64 ... Roy Skinner .. 19-6 ......... -- **
1965-66 ... Roy Skinner .. 22-4 .......... 8 **
1967-68 ... Roy Skinner .. 20-6 ......... -- **
1972-73 ... Roy Skinner .. 20-6 ......... -- *@
* Final AP Poll included only 20 teams.
**Final AP Poll included only 10 teams.
@ I am reminded by CharlieNickens in this VandyMania thread that Vanderbilt was ineligible by virtue of hosting the 1973 Mideast Regional.