Well isn't 100 pages enough? Also you can set time range to get access to earlier games.
Bug [ ]: Archive query does not consider all games

Well isn't 100 pages enough? Also you can set time range to get access to earlier games.
If I want to review all my Pirc games I can't.
Also setting the date prior to the first 100 pages has no effect as the date range considered is only the dates of the first 100 pages. So one can't see older games.
No it has an effect.
These are your games prior to 2017:
And these are the games with no time range set:
So this is by no means a bug.

There is a limit to the number of games that explorer will retrieve. I'm pretty sure it is a method to reduce database load.

There is a limit to the number of games that explorer will retrieve. I'm pretty sure it is a method to reduce database load.
This is true. We are looking for ways to expand it, but cannot yet.

There is a limit to the number of games that explorer will retrieve. I'm pretty sure it is a method to reduce database load.
This is true. We are looking for ways to expand it, but cannot yet.
Date qualified query does expand the database view beyond/outside the first 100 pages. It is limited to returning only 100 page but does see back beyond the 100 page recent games. The issue is additional qualifiers, in addition to the date, like openings, fails to return anything.
Ideally a Sicilian search, not date qualifier should return all Sicilian games, Less good would be 100 pages of Sicilian games. Currently the query gets 100 pages of games and then filters those by opening. This will less than the actual number of Sicilian games and not 100 pages of Sicilian games.
The query composition should permit Select Opening=Sicilian and see past the 100 page limit of recent games in the same fashion as Select StartDate=1/1/11 and EndDate=1/1/14 sees beyond the 100 pages of recent games.
Ideally Select Opening=Sicilian and Select StartDate=1/1/11 and EndDate=1/1/14 should work as well.
Eliminating the 100 page limit would be great. Minimally not pre-filtering down to the 100 page limit and then filtering on the opening, but filtering on the opening, then limiting to 100 pages would be much better.

This opening qualifier issue is still present when querying.
Recent work/improvements has addressed some of the other issues. A date qualified query will return 100 pages and if you ask for oldest to get 100 pages starting with the begin date.
The new result qualified queries:
also consider more than the latest 100 pages of games. Very nice improvements.
This query
yields no results
as opening qualified queries are still restricted the latest 100 pages of games even with the date range is outside the latest 100 pages of games.
Bug: Archive queries should consider all games, not just the first 100 pages.
Doing an opening query, as in the Pirc example above, only presents results from the first 100 pages not the entire game history.