Numbering the games

It's not clear how various developers, critics and advertisers number the series, or which games they count as the main part of the series. Starting with Wolfenstein: The New Order it was said to be the "Ninth" game in the series, and The New Colossus is said to be the 11th game in the series.
Nor is it known if that numbers includes the original Castle Wolfenstein or Beyond Castle Wolfenstein.
Of the Id series and later games in the series (some with very little or no involvement by Id including  MachineGames current 'reboot/soft reboot') the most likely to be counted (not including expansions or true remakes) would likely be:
# Wolfenstien 3D
# Wolfenstein 3D: Spear of Destiny
# Return to Castle Wolfenstein
# Return to Castle Wolfenstein: Enemy Territory
# Wolfenstein RPG
# Wolfenstein (Wolf2)
# Wolfenstein: The New Order
# Wolfenstein: The Old Blood
# Wolfenstein II: The New Colossus
Even counting Wolfenstein RPG and Enemy Territory (one game which plays differently mechanicallym and the other which is a stand alone multiplayer games) it still is less than 11 games.
While adding in Castle Wolfenstein and Beyond Castle Wolfenstein (does appear to add up to 11 games including Enemy Territory and the RPG as part of the official counting):
# Castle Wolfenstein
# Beyond Castle Wolfenstein
# Wolfenstien 3D
# Wolfenstein 3D: Spear of Destiny
# Return to Castle Wolfenstein
# Return to Castle Wolfenstein: Enemy Territory
# Wolfenstein RPG
# Wolfenstein (Wolf2)
# Wolfenstein: The New Order
# Wolfenstein: The Old Blood
# Wolfenstein II: The New Colossus
In both of these countings, however, would not take into account ports/remakes like The Claw of Eisenfaust/Original Encounter/2nd Encounter. This is fair if you consider Original Encounter and 2nd Encounters to be similar to Expansion Packs, or simply ports/remakes. Likewise Cursed Sands (Tides of War/Operation Resurrection) should only be considered an expansion to RTCW (rather than a stand alone game, 2nd Encounter/Original Encounter as packed in with Mac and CDI versions of Wolfenstein 3D would simply be expansions/remakes to Wolf3D).
The Old Blood is somewhat of a remake of RTCW, but it's also a stand alone PC game. But if only PC games count, then Wolfenstein RPG should not count either, despite it being an original game (albeit perhaps a loose retelling of some of the events of Spear of Destiny).
Some would not count Enemy Territory, Castle Wolfenstein, or RPG in the 'main' counting (and some only count Spear of Destiny as a stand alone expansion to Wolfenstein 3D, despite it having its own set of expansion). But assuming that at least Muse games, Wolfenstein RPG and Enemy Territory do not count then it leaves only seven games (which is still under the counted 11 in the New Collossus counting).
# Wolfenstien 3D
# Wolfenstein 3D: Spear of Destiny
# Return to Castle Wolfenstein
# Wolfenstein (Wolf2)
# Wolfenstein: The New Order
# Wolfenstein: The Old Blood
# Wolfenstein II: The New Colossus
While counting only B.J. Blazkowicz or ID related games (including 2nd Encounter/Original Encounter/Eye of Eisenfaust, as there is evidence that references in The Old Blood and new Collosus relates to that game) would still only add up to 10;
# Wolfenstien 3D/Wolfenstein 3D Classsic
# Wolfenstein 3D: Spear of Destiny
# The Eye of Eisenfaust/Original Encounter/2nd Encounter
# Return to Castle Wolfenstein
# Return to Castle Wolfenstein: Enemy Territory
# Wolfenstein RPG
# Wolfenstein (Wolf2)
# Wolfenstein: The New Order
# Wolfenstein: The Old Blood
# Wolfenstein II: The New Colossus
Maybe counting Cursed Sands related ports/remakes would add up to 11.
# Wolfenstien 3D/Wolfenstein 3D Classsic
# Wolfenstein 3D: Spear of Destiny
# The Eye of Eisenfaust/Original Encounter/2nd Encounter
# Return to Castle Wolfenstein
# Return to Castle Wolfenstein: Enemy Territory
# Cursed Sands
# Wolfenstein RPG
# Wolfenstein (Wolf2)
# Wolfenstein: The New Order
# Wolfenstein: The Old Blood
# Wolfenstein II: The New Colossus