1933? I thought the Senators went to the playoffs after that, just didn't go to the WS. Or am I wrong.
No playoffs until 1969, when both leagues split into east and west divisions. Nationals (aka Senators) did not go to post-season after winning the pennant in 1933. Came close about 1945, when MLB was played by non-regulars. I think the Browns won the pennant on the last day, after a Senators (OK...they were officially the Nationals) OF forgot to take his sun-glasses to the field and lost a fly ball in the sun. Not a great record, and that roster has some strange names...I think the great Cecil Travis came back from the war, but had suffered frost-bitten toes during the Battle of the Bulge. Couldn't hit the way he hit in 1941 (something like .350). Travis has been called "the finest ball-player never to get a single vote for the Hall of Fame". He deserved it: gave up a Hall of Fame career to serve in WW2...and not just serve as a recruiting symbol.
Some very old players, and some players who went back to obscurity the next season.