Dumb question ahead: when people talk about a track having a leader's bias on a day, what does that actually mean? The inside rail position is running much faster so it's hard to overtake from 2 or 3 wide, or just generally that the track is slow so it's hard to wind up and reach a top speed?
Could be either.
If the track is even but rock hard it generally favours leaders because of the required speed to make ground from the back. Also horses don't tire as quickly on hard tracks.
Then there are situations like Winx first CP and multiple Derby Days where there is a "fast lane" which is quicker than the rest of the track. Often on the inside fence but could be in other parts. At Flemington there's also a fast lane down the middle where the sprinkler packs the track down harder, plus it has a different type of grass on the inside 2-3m.
Then you have tracks which when they get wet heavily favour the outside rail due to the camber, similar to Oakbank on the weekend.
Lastly you have situations where the track changes during the day due to traffic. Inside is best going early then it chops up and wide becomes the better going