The graphic layouts shown give those new to VTPR Aerobatics a rudimentary idea of the playing field. It tries to focus the plane orientation to the slope and every slope topography is different. The arena would need to be laid out as needed to gain the best advantage of the prevailing wind conditions the day of. Pilot box could also be situated in a way that the pilot prefers to see his plane through the arena. In a competition the pilot box may be more strictly located by the referee. You'll note the four corner poles. These define the minimum height level from the ground which so far seems to be best set at 10 feet. These are used as pilot sights or gauges. The goal in VTPR is to place the model as close to the deck as possible without crashing.
The 10ft maximim height rule and below is the established Vtpr performing "sweet spot". It also allows some headroom to ease into the 0-6 foot "danger zone" within the arena or can be used as a comfort zone height. Typically there would be no penalty for flying outside the fly-box perimeter. Vtpr by nature is very unpredictable in it's windage and lift conditions requiring the pilot to constantly adjust his flight path to maintain proper model momentum throughout the run or heat.