During the final decade of the 20th Century, only two teams compiled large home-road disparities. Both did so early in the decade.
The 1990 Houston Astros reprised the Astrodome’s reputation for home cooking. Season-long they were below average, with only a 75-87 record. Under the Dome however, the Astros played championship ball, winning 49 of their 81 starts, a .604 winning percentage.
The problem, obviously, was Houston’s wanderings. Away from home the Astros went 26-55, losing seven of nine road games to the eventual World Series winning Reds. At home the Astros out-scored opponents by 26 runs; away from home opponents out-scored them by 110 runs.
The 1991 Cardinals finished 14 games behind the NL East champion Pirates, and that entire 14 game difference could be found in performance on the road. Both teams went 52-32 in their home parks, but while the Pirates played 46-32 ball on the road the Cardinals stumbled to a 32-46 road record. That included losing six of nine to the Pirates in Pittsburgh.
Despite being in second place in their division during all of August and September, the Cardinals compiled an 8-21 road record during the season’s final two months. For that same period at home, they were 23-10.