He explains how it works. Picking the best route on the map and sticking to it on the trails is important.
"In the afternoon, there are some sprint events, usually with only a handful of controls, and short distances between. These test memory and accuracy.
"On Sunday there's a two-hour time limit to visit controls, each with different points value. You choose which controls to go to, and how, and the one with the highest score wins. You have to work out which controls aren't worth the effort."
It makes for a lot of thinking on your seat and a good challenge of balancing mental and physical strength.
"It's a fun challenge to ride hard enough that you set a good time, but no so hard your brain struggles to keep up and you end up lost. It is a very fine balance and, in my experience, the head always goes before the legs so you don't always know it's coming."
Randal said the Whakarewarewa trails were ideal for MTB orienteering. "Wellington trail riding is much narrower and steeper, but has great views."
Rotorua tends to have a much nicer flow, and can be enjoyed by riders with wider ranges of ability and fitness. The trails are particularly fun when you're part of a group.
"From an orienteering viewpoint, it is always nice to ride somewhere unfamiliar. I don't know the trails that well, and to the extent that I do, I'm not used to seeing them on a map. That can lead to a fair bit of confusion at times, but that's the challenge of the sport, and I find it exciting."
With a lot of crossing and overtaking there is also the chance for plenty of camaraderie and banter on the trails.
"You often hear things like, 'Where did you come from?"'
You can end up riding with someone briefly, and it can be quite distracting when they disappear in one direction while you "confidently" ride off in another.
"It's cool to catch up afterwards and swap notes. Last year, I raced past Brent Simpson in almost exactly the same spot in two different races - we had a good laugh about that afterwards, especially as he beat me in both."
