"Tom Ogilvy" wrote...
the OP said:

This needs to be done using a single formula or array formula,
without using a separate running total column using =MAX, and
without using a UDF.
....
. . . however, this person said they were evaluating a "this
can't be done in a single formula" challenge.

Not sure why he posted in programming instead of the more logical
Worksheet.Functions

Indeed, so I'm crossposting to worksheet.functions. Follow-up there.

Of course it can be done in a single array formula - just barely.

If the data were in a single column by multiple row range named rec, then
try the following.

=COUNT(OFFSET(rec,MATCH(MAX(
MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec)))
-(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec))),
--((rec<0)*ROW(rec)=TRANSPOSE(ROW(rec))))0),1-(rec<0))),
MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec)))
-(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec))),
--((rec<0)*ROW(rec)=TRANSPOSE(ROW(rec))))0),1-(rec<0)),0)
-MAX(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec)))
-(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec))),
--((rec<0)*ROW(rec)=TRANSPOSE(ROW(rec))))0),1-(rec<0))),0,
MAX(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec)))
-(MMULT(--(ROW(rec)=TRANSPOSE(ROW(rec))),
--((rec<0)*ROW(rec)=TRANSPOSE(ROW(rec))))0),1-(rec<0))),1))