XII is the Vienna: Frankenstein-Dracula
The odd opening position
Wow! I thought with the full boards instead of sections I would do better at
this puzzle but I guess not as this is difficult as well.

VII is french winawer right? and IX is sicilian maroczy bind
Winawer is correct, but for IX even though it shows a Maroczy bind structure, I am looking for a specific variation...

I. King's Indian: Exchange Variation
II. King's Gambit: Double Muzio
III. Sicilian: Pelikan Variation
IV. (Some 1. e4 line)
V. (Some Dutch line)
VI. King's Indian: Four Pawns Attack
VII. French Defense: Winawer Poisoned Pawn
VIII. Queen's Gambit Declined: Lasker Variation
IX. (Some English line)
X. I would guess Scotch: Four Knights?
XI. (Some King's Gambit line)
XII. Vienna: Frankenstein-Dracula Variation
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Standard opening variations of well-known openings are shown below. Can you name both the opening and the variation? All positions except one share a common characteristic. Can you spot the odd position out? Hint: the common characteristic is mathematical in its nature.
[Congratulations to Rooperi and Checkmateisnear for solving the main question; all positions except VII show the board after white's 10th move. VII shows the board after white's 14th move.
All positions are now solved:
I.King's Indian:Saemisch; II.King's Gambit:Muzio Gambit; III.Sicilian:Pelikan/Shveshnikov;IV.Ruy Lopez:Schliemann; V.Dutch:Leningrad;VI.Benoni:Taimanov;VII.French:Winawer;VIII.Queen's Gambit Declined: Lasker;IX.Sicilian:O'Kelly;X.Ruy Lopez:Cozio;XI.King's Gambit: Allgaier;XII.Vienna: Frankenstein-Dracula]