Now it can be told...SS obstacles and Flitwick's position

[foxmoth at qnet.com]

No: HPFGUIDX 4622

Devil's Snare, Sprout, head of Hufflepuff
Keys: Flitwick, head of Ravenclaw
Chess: McGonnagal, head of Gryffindor
Troll: Quirrel
Potions Puzzle: Snape, head of Slytherin

Do you suppose JKR concealed the identities of the heads of Hufflepuff 
and Ravenclaw in the first book so as to keep it from being obvious 
that Quirrel was the odd man out?