...
Fewest Places Remaining would be a lot more useful than Registered Players or Max Players. e.g. (see 3rd column)
..
Ideally, sorting by Fewest Places Left (column 3) would favour larger tournaments over smaller ones (with equal numbers of places remaining) ...
RSS feed = waffles.
As a starting point, the key parameters that I would be interested in are:
e.g. show me upcoming (multi-day) tournaments where
rating range is 1400-1600 AND
time control > 3 days AND
%places filled > 60%
For simplicity, assume the rating range has to be wholly within the specified target; so 1450-1550 would satisfy 1400-1600, but 1300-1500 and 1500-1700 would not satisfy a 1400-1600 requirement.
For simplicity, unlimited entry tournaments (such as official chess.com ones) could be classed as ALWAYS satisfying the %placed filled criterion.
It becomes simpler if the upper and lower rating ranges are considered separately.
Open would be mapped onto 0 .. 9999
< 1600 would be mapped onto 0 .. 1599
> 1600 would be mapped onto 1601 .. 9999
Then a query can be expressed in terms like this ...
e.g. show me upcoming (multi-day) tournaments where
upper rating limit < 1601 AND
lower rating limit > 1399
time control >= 3 days AND
%places filled >= 60% AND
NoVacation = FALSE
A fairly straightforward interface would be to copy the Game Settings for Challenges e.g.
Tournament Search Settings
Rating Limits: Min 1300: Max
Days per Move: Min 3 : Max 10
Official? Yes 8 No 8 Don’t Care =
No Vacation? Yes 8 No = Don’t Care 8
Thematic? Yes 8 No = Don’t Care 8
960? Yes 8 No = Don’t Care 8
Places Remaining (Max): Number 1300 or %
(The Upcoming Tournaments query is already customised for each chess.com member, since the list you see depends on your current rating, and whether you have premium membership.)
i really wish they had this feature.
Well this feature should be 13 months nearer to being offered than at the last time I looked. 
"Well this feature should be 13 months nearer to being offered than at the last time I looked. "
Hmm. Just missed the 4-year anniversary.
If the Upcoming Tournaments information were provided as an RSS feed, that would be much easier to process.