Are you people serious? It's not pre or post-Automatic and it's not I.R.S./Warner Bros. either. The division is between Green and Out of Time. Before Out of Time, they were a college radio band with a very large cult following and a few big singles. After the Green world tour, these guys made a complete left turn and made a lush, pastoral album (albeit one which leads off with a guest spot from a rapper!) that was their first #1 LP, and also turned them into a huge crossover act. Their decision to not tour that album (or the next one) is another distinguishing point, as is all the instrument-switching that went on between Berry, Mills, and Stipe. And in another new practice, the album was recorded over a longer period of time in various locations.
While Green is a piece of shit next to Document, I look at it as an inflating of their typical sound/style, but nothing that sounded totally out of the ordinary. The only hint towards what they would do next is You Are The Everything (which IMO also happens to be the best thing on there along with World Leader Pretend).
Of course, two albums later they did Monster, but even though the album might seem to have a lot in common with Green, I think songs like Strange Currencies, Tongue, Let Me In, I Don't Sleep I Dream bear the influence of the wider sound they had explored on Out of Time and Automatic. And of course Hi-Fi and Up blended all this together.
The next dividing line really is between Up and Reveal, because even though Berry was missing on the former, they went in a more abstract direction, eschewing a standard drum sound on most of the songs, and experimented in a way that bears zero resemblance to the two miscarriages that were subsequently released.
In short:
Murmur
Reckoning
Fables of the Reconstruction
Lifes Rich Pageant
Document
Green
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Out of Time
Automatic for the People
Monster
New Adventures in Hi-Fi
Up
--
Reveal
Around the Sun
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Accelerate