Yes, a foolish mistake. Bank was played with ventilation, which meant that Mill Hill East counted as three things: terminus, branch line, and Northern Line anchor (class X). I completely forgot about the branch line aspect, and I notice (without much rancor) that Ianzin didn’t mention it in his play. Not that he was technically required to, but … well, 'nuff said.
Really? You think we wouldn’t notice an attempt to tie a Featherington’s Knot? The old boy himself has disavowed the knot as hopelessly flawed and would be turning in his grave; watching the play so far, one would think the hypermoderns never existed.
Vauxhall
(And lest you be inclined to chide me, I’ll point out that the King’s Cross Gambit has already been declined).
Pimlico. And tweak the noses of the separatists.
Actually, Featherington’s Knot was proved to be solvable in n(log n) steps when anchored in either the Jubilee or District Lines. Singh and Priyan did a paper on it last year, cite on request.
Er… not that I was angling for that easy out. Not me, nosireebob.
Marble Arch.
Duplicating affirmative action with Elephant & Castle.
I take it you missed Singh’s partial retraction last month. It turns out Privan was making up some of his data. You can still solve the knot, but you need at least three anchors, two of which must be the Central and District Lines.
That issue is still sitting on the nightstand, unread.
Well, it’s moot anyway given the Vauxhall play tying down everything towards Walthamstow Central.
Not sure whether lynne-42 was making a clever pun or a foray into rhyming slang with her Elephant & Castle play, but I’ll answer it with Frog & Toad: Holloway Road.
Kentish Town
two more brass tokens discarded.
Finsbury Park with declared congestion and a labour slowdown. This reduces the efficacy of the Northern line by 15%.
Ha! I’ve been waiting for a Northern Line Slow Down!
Camden Town, discard all remaining brass tokens. I think I can now safely force MC in 18!
Crap.
Pardon my French if you’re a religious person.
OK, Hatton Cross, sinking six on Piccadilly to Northern and three on Northern to Piccadilly. If anyone else wants to step up and complete the classic Viscount Asquith Manoeuvre now, please feel free.
ETA:
Never mind. 
Against Camden Town I’ll play it safe. Holborn and a declared rail crash. (I apologize for the poor taste in declaring a rail crash in this of all stations.)
After Bricker declared a rail crash, it seems to me that Stockwell disrupts your claimed forced MC. So Stockwell it is.
Ah. We are clearly now in the beginning of the middle of the end of the beginning of the endgame.
This is where my game usually falls apart; I can usually stake a good striking position (especially playing with Nibs) but I invariably miss a subtly-played line delay. Though I still question the legality of leaves-on-the-line (and yes, I’m looking at you, Mr. “I can’t believe there’s someone who would recognize my play style so long after that 43rd Tottingham Amateur Open Controversy” Bricker - did you think you could hide it, even after these years? Your fans worshipped you, sir, and you repaid them… but I digress).
Well, going for broke now: Finchley Central, discarding a one-day, 4-zone travelcard (please tell me we’re playing off-peak here).
Well, you posted at 1612 GMT, so you’re good. I’ll respond with Lime Street.
I admit nothing, but still ask that you avoid using my real name here, just in case you’re right. 
Lime Street answered with: Stepney Green, doubled.
I’m going for a Circle line split with Aldgate East.
Back to Marble Arch. Pick up one silver token, at least.
Marble Arch, eh? I slide over to Notting Hill Gate and call Tumpington’s Divergence.
(That Tumpington was quite prolific just before the Great War. Journal articles, original research, even a popularization in The Illustrated Londion News. My Grandfather claimed that as a young man, he’d seen him play uninterrupted during the entire three-day span of the 1908 MC Test Invitational, and then take on Featherington-Smythe in an amateur match without so much as a nap betweentimes. Personally, I suspect the Big T had perfected the art of sleeping with his eyes open. I know that’s come in handy for me…)