Well, the Washington Post's Peter Marks (the former #2 critic for the NY Times), for example, simply takes the train up from DC and attends the same critics' previews as all the NY-based critics, so his reviews generally appear in the Post the same day as all the reviews in the NY papers (by the way, any way we can make a trade and let DC have Brantley? Marks is SO much better). DC's theatre scene, while very good, is obviously considerably smaller than NY's, so it's possible for him to attend all the productions by Arena, Studio, Wooly Mammoth, the National, the Shakespeare Theatre et al, and still make it to all of the new Broadway (and major off-Broadway) shows. I imagine the critics from the Hartford, Philly and Boston papers do something similar, though it must be more of a challenge for critics located outside the northeast corridor.
The thing is, other than Chicago, DC, San Francisco, LA, Seattle and a few others, most cities just don't have that much new, interesting, professional theatre going on. Most publications outside of these few cities, to the extent they cover theatre at all, generally have an arts editor/critic who wears multiple hats covering local theatre, dance, music, gallery exhibits etc... The members of the Outer Critics Circle are those rare lucky folks that work for publications that put enough value on having a Full-Time theatre critic and are willing to pay for frequent trips to NY. Like Marks, they can handle their duties covering whatever's going on at their local theatre companies and still have plenty of time to make it to all of the major shows in NY throughout the year. Not a bad life.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
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"The Devil Be Hittin' Me" -- Whitney