usual follow up question:
'If it's too deadly for sport, how do you spar, and therefor know it works?'
We do spar, but the mentality is not sportive but survival-oriented. For example, in the Hamilton club we often end up sparring over tile, and our sparring includes takedowns.
If we were to have the outlook of a sports grappler, this would be dangerous. The sportsman doesn't want to be taken down, because being taken down would involve loss of 'points'. In systema, being taken down can be a bad thing, insofar as you might take some impact or end up in a bad position, but there is no concept of 'points'. Therefor, if someone is taking you down and you cannot maneuver/finesse out of it, it is perfectly acceptable to roll under your own volition , rather than waiting for the throw to complete. In this manner, impact is minimized, and there are various counters available to you i the roll. Survival over 'winning'.
In a similar vein, the 'point' concept in sportive striking is lost. Hitting is a byproduct of sound movement and positioning rather than something you deliberately set out to do. Simply touching someone with your fist is meaningless, unless you have the body mass and structure behind it to make it count.
In groundwork as well, it is not seen as neccessary to try and pin someone down and submit them. Much of the gorundwork we do revolves around flow and escape, and in a sportive context, trying to escape from a grappling match would be penalized. In fact, there are many times on the ground where you have the option to disengage, yet people are conditioned to keep going for the pin. As demonstrated by Fedor against Mino last weekend in Pride, much of the attacks from the gaurd are really counters to attempts to pass, and often you have the option to leave if you forget about passing. In fact, from a systema pov, the fight was over when Fedor walked out of the gaurd the first time. In RL, if a guy is on his back just lying there and you're standing, you should just walk away. Although in sparring, we'd probably attempt to put the boot in, just to keep things interesting.
And lastly, unlike sports there are no rival 'teams' or clubs in systema, because we are all one family. The camaradery that you might see within a really competitive judo/bjj club is there, but with none of the rivalry towards outsiders - everyone in systema is in the club. I liken it to what the 'mutual welfare and benefit' aspect of judo but applied more universally in practice than it is in judo culture.
At least - that's what we aspire to. Truth be told, competition is part of human nature, and so our ability tends to wax and wane in inverse proportion to our egos, which provides different kinds of challenges to our training partners - so it's all good, I guess.