Something occurred to me when Googling around for the best exercises for Armwrestlers. Let's say you want to simulate (not train for!) the AW in the gym - best way is to lie flat on your back, elbows pointed out, dumbells at head level, and bring the bells over to hip level. Possibly not great for the RC either, and the ACTUAL training methods for Armwrestlers are wrist/forearm work, but that's an aside. I'm just using the movement as an example.
The other trouble with that movement is that you cannot simulate the opponenents micro-variations in fatigue that he would experience. You could try doing the same using a pulley, but not oiling it so that the load is uneven during the movement (I found this on my own lat tower).
So you could could train in an almost frictionless manner with dumbells/pulley, but when faced with an opponent used to fluctuations in his strength vs an opponents, not to mention actual hands-on experience (pun not quite intended but not far!), the undertaking would have a very unfamiliar feel to it.
My question here is, is there a term other than friction, for those micro-variations within a force that you would not find when a weight is simply being pushed through air, or that are minimised when you oil the pulley cable?