I guess I was confusing concessions within the park proper with those private Game Reserves adjoining the western boundary of the park. eg. Thornybush Reserve.

The Klaserie Fence in Balule Reserve only came down two years ago and there are some lodges adjacent the KNP which don't have access to the park proper. There's plenty of landowner politics with regard to transversing rights.

The fences haven't always been down, and I haven't been to a private concession since 2003, instead enjoying the SanParks accommodations within Kruger.

That should be changing now for me, as the wonderful in-laws now sharehold a lodge within Balule which allows 3 week long visits per year with a private game viewing vehicle

What I meant by the zoo comments is that in certain private reserves eg, Sabi Sand as a good example, animals have been so conditioned to the approach of vehicles as to totally ignore them and with the sheer number of game drives from all the lodges and radio coordination with report back to all lodges amongst the guides there is a better chance of spotting game at a closer range in a smaller area than you would in the KNP proper. In fact it is all but guaranteed that you will see 4 of the big 5 (Leopard excluded) during a 3 day stay at a private lodge in Sabi Sand, Manyeleti, or Timbavati. Not so on a self-drive in the park left to your own devices.