Hey Yeti,
You may not know but there will, in effect, be two train lines (not one). That is, when crowds are travelling to the stadium, trains will run from the city on both lines (mains), not just the normal outbound main (the down main) but also effectively in the wrong direction on the normal inbound main (the up main) - ie towards the Stadium. Situation is reversed when crowds empty. People on Midland line won't be happy as the footy specials will terminate at East Perth Station and they will have to walk from there unless they want to travel into the city and back out again on a normal Midland service. I understand both Claisebrook and McIvor will be bypassed by footy/stadium specials when events are on. Big winners are those travelling from the North as their services will run through the city straight to the stadium. Probably as clear as mud but thought you may be interested.