Microsoft technical article 832524 states:

"The -T1205 startup parameter collects information every time that the deadlock algorithm checks for a deadlock, not when a deadlock is encountered. You do not have to use the -T1205 startup parameter. "

Anybody know WHEN this behavior began, because I know at one point 1205 only provided some extended info over and beyond what you'd get from flag 1204.

In fact, the above wording is suspicious - including the phrase "...not when a deadlock is encountered..." is clearly there to correct the impressions of those of us stunned by the new behavior. The errorlog file will grow FAST now if you turn on 1205........

I'm pretty sure this was not the case with the initial release of SQL2000, must be in a service pack, but I don't know which - haven't used 1205 in a while. All over the web are pages documenting the behavior of 1205 as used to be, but I can't find any indication of when this behavior changed, which would be useful in an root-cause-analysis I have to write.