For the benefit of elizabeth plus any lurkers, here's the explanation I was only going to give if you needed it, because apparently you do. Mornington Crescent is a game invented almost 40 years ago by people writing for BBC Radio for the sole purpose of annoying a producer who was an intellectual snob. The idea was to create a game so elaborate that nobody could possibly figure out the rules unaided, then pretend that it was so well-known that no explanation was needed, thus putting this guy in a position where he couldn't bring himself to ask what the heck was going on for fear of looking ignorant and stupid, and therefore had to pretend to understand the rules, not realizing that everybody saw through his bluff because they knew they'd made it all up and explained it to nobody. The game works on 3 levels. Firstly, the basic idea is absurdly simple. The first player can name any station on the London Underground except Mornington Crescent. Everyone then takes turns to name a station which links up with the previous one, and whoever gets to Mornington Crescent wins. The second level is that the moves permitted between stations (or, in more advanced versions of the game, between thousands of other locations as well) have absolutely nothing to do with how the actual stations physically connect up. Instead, they're governed by insanely complex rules allegedly going back centuries which you'd need a lifetime's dedication and an IQ of 800 to fully understand. Any player may at any time challenge anyone else's move if they think it contravenes an obscure rule they happened to remember. It's also considered polite to compliment any moves that go unchallenged, citing the subtle rules that player has cleverly taken advantage of. There is usually a referee whose word is unquestionable, who tends to take a very active part in the game, frequently disallowing moves that are illegal because of some rule so obscure that nobody remembered it (most players find it particularly difficult to remember which moves will put them in Huffingtons). The third level is that there aren't really any rules whatsoever. The only rule that actually applies is that, whenever any player for any reason decides the game has gone on long enough, they can instantly win by announcing they've reached Mornington Crescent. This is the only move that's never challenged, because everybody else automatically assumes it was both valid and clever. The skill of the game lies in justifying every move you make by quoting incredibly complex rules that you made up on the spot, sometimes combining them with rules which, over the years, have been mentioned often enough to be almost comprehensible as actual rules (though not quite) and are therefore an established part of the game and can be found online. For example, being in Huffingtons is a severe penalty condition which can occur either as the result of a bad move, or because another player forced you there by making a very good move. However, since being in Huffingtons costs you points, and winning the game doesn't actually involve the number of points you have, it's not clear why this should matter. Though of course any player in Huffingtons is obliged to be upset about it. All moves can be challenged, though any challenge can be counter-challenged. The basic rule here is that any challenge will work if it sounds convincing enough, unless it's met fairly quickly by an equally eloquent counter-challenge. Since none of the rules are ever really explained, if a player wishes to justify a move by citing a rule which almost makes sense, it is customary to explain this rule only in terms of how it affects an even more obscure rule, which is of course not explained at all. In general, all players who are challenged must accept that challenge if they can't come up with a more eloquent rebuttal, but if they can, the challenger should nearly always admit they were wrong, unless they can come up with something even better. Compliments for good moves can be made at any time, and are assumed to be entirely valid, as are any rules they quote, so a wily player may congratulate somebody else on a clever move using a very obscure rule, then use that rule themselves on their next move. Which would matter if this was an actual game you could actually win. Does everybody get it now?
Oh, by the way, I don't know whether it's true genius or just beginner's luck, but by choosing Vauxhall, a classic though frankly predictable first move, as her extremely unorthodox second move, elizabeth has blocked my progress up the first quadrant I was hoping to dominate by taking King's Cross. In fact, as a result of the Gruntfuttock Amendment (remember - this is the Mousebender Variation with no Double Huffingtons), I have no legal moves other than to redouble myself and hope she makes a mistake. Therefore, Finsbury Park again. (See how this works...?)
A further clarification. Apart from Huffingtons, the worst penalty condition is to be in Nidd. This is a river in Yorkshire which features in every version of the game, and in the beginner's version is assumed to be part of the London Undergound, despite being a long way away and not a railway station or anything resembling one. If you're a novice player who happens to be French and are therefore playing Mornington Croissant, the River Nidd is also part of the Paris Metro. Being in Nidd is such a long-established rule that it almost makes sense, since the consequence is that you have to miss a turn until you're out of it, which differs from Huffingtons in that you're forbidden to move into Huffingtons on purpose but may do so by mistake, the consequences of which are baffling but temporary. Nidd, on the other hand, means that you get no moves at all until the referee decides you're out of it, which may take some time. Prior to 1903, since Nidd is technically a London Underground station, deliberately putting yourself in it was a legal move, so long as it was perpendicular to a line between two points, thus making it the shortest distance. However, once the offside rule was introduced at the championship level, the prohibition on moving south of the river, which was meant to apply only to the River Thames, meant that putting yourself in Nidd, and thus in a river a long way north of London, put every other player in Quadruple Huffingtons. It was this glaring loophole which caused five-time world champion Hezekiah Pipstraw to lose the Clothtoucher Cup to a tortoise. I trust that's all clear. In any case, it has always been an illegal move to put yourself in Nidd on purpose in January, because you'll probably get pneumonia.