Anahita please be aware that, as I explained before, the basic gameplay in Mornington Crescent (MC) is fairly straightforward, and you can have a lot of fun without needing to master some of the more advanced conventions and strategies.
Please also be aware that those of us who have, for better or worse, learned some of the more arcane MC rules and techniques tend to show off a bit. This is all good-natured, and considered by aficionados to be part of the fun of the game. However, many of the situations and rules we’re discussing only occur very, very rarely in actual play, and hence need not trouble beginners (I’ve been a keen MC player for years and I’ve never used the Ruislip diversion yet, cunning though it is.
ObiWan, I don’t pretend to be an expert, just a fan of the game, but the reverse Ruislip doesn’t revoke Stirrups, but can over-ride Stirrups for one turn or consecutive turns made in the same direction (as if that would be much use!). The '94 semis, if you recall, included a Harris Rules section, non-Gibberty, so that’s why Tamkin could get away with it. I expect we’ll be sticking to Gibberty, which is a relief (I can’t remember most of the Harris rules these days and have to look them up!).
Also, if I’ve got this right, Shirokane-Takanawa was declared non-canonical under Gibberty after the Bruges summit of '98. If you recall, Tamkin had proved that, following motion West (Bassingtons in play), MC can always be reached in 3 if the S-T is in effect. Hence the S-T is slightly pointless.
Consider this from Simmington .v. Goossens, Helsinki '97:
Latimer Road (Bassingtons) ; Gospel Oak
Blackfriars ; Acton Central
East Acton (!) ; Acton Central (Stirrups rv)
Seven Sisters ; Perivale
at which point Gooseens declared MC in 3 against any defence e.g.
Swiss Cottage (hoping for a ‘Town’ or ‘Park’ error ) ; Aldgate
Park Royal ; Aldgate East (!!)
ANY : Mornington Crescent
See what I mean?