What was the worst offensive performance in Major League postseason history?

Well, those 1966 Dodgers 'were' pretty bad (World Series records for most consecutive innings shutout, most consecutive batters struck out [tied at six with the 1919 White Sox, a team 'trying to lose'], and Willie Davis' WS record three errors in one inning, leading to three unearned runs...). They hit .142 in that series.

The 2010 Reds went from being the highest-scoring team to being no-hit, being shutout another time, and scoring 4 in one game, hitting an anemic .124 in the series- the WORST batting average of a team I could find (of course, I only checked sweeps).

The 1999 Texas Rangers scored one run in three games against the Yankees in the ALDS (vs. the Yankees' 14), getting swept by the Yankees the 'second year in a row.'

The 1998 Rangers ALSO scored 'one' run in three games against the Yankees in the ALDS, hitting .141 total (they were at least 'slightly' better in 1999).

Honarable mention: While not an 'official' World Series (because, I mean, none of the teams who won those things before 1903 count them in their World Series totals...), the 1884 World Series saw the New York Metropolitans hit .147, and the Providence Grays' ERA was 0.00, over three games (all pitched entirely by Old Hoss Radbourn). Meanwhile, the Metropolitans' ERA was 5.57.

The Metropolitans were an American Association team, of which only the Cardinals survived, and the Providence Grays were a National League team who folded after the 1885 season.

This is the most disgraceful performance i have ever seen. Safe to say congratulations to the AL Champions the Detroit Tigers.

Thank you.