We never really found ourselves using the thumbwheel in our first-person shooters, but you can think of it as a two-way rotating programmable button if you will, and it spins in small enough increments to find use as a weapon or ability switcher.
An active palm rest rounds out the modules, with a thumb-wheel and additional action button -- it's joined by a pair of (yet again) adjustable wrist rests that anchor along the bottom edge.
In a world of multiple connections, where the distribution of future probabilities cannot be known (unlike the probabilities involved when spinning a roulette wheel), simple rules of thumb may be more useful than sophisticated models.