This discussion sort of emerged in the other thread, but I thought it was pretty off topic there, and really deserved its own thread.
I'm a pretty firm believer in contact sparring; Sparring in which you actually hit or grapple with another person. I feel that the only way you can learn to hit or grapple with someone is to actually hit or grapple someone.
Does anyone feel that you can develop such skills without contact sparring, or no sparring at all?
For martial sports, sparring is required and necessary to properly develop the skills needed for competition. For a martial art (that is focused on self defense rather than esoteric aspects), sparring is detrimental to properly developing the skills needed. Sparring, in the context one would normally associate with the term, is limited in scope and focus. It involves two participants that abide by a restrictive skill set (based upon the art in question), in a specific setting for a specific period of time. This is not conducive to realism. This isn't to downplay the importance of sparring for sport which, as I stated, is necessary. Scenario based training is far better for a martial art, that has a focus on self defense as it doesn't restrict itself to a specific venue or skill set or rule set.
As an example, I've taught over 1000 students, most of which are high liability professionals. We do zero sparring. We focus on scenario based training which allows the venue to change (inside, outside, woods, alley, inside a car, in an elevator, on stairs etc), the number of attackers to change, dim light or no light situations, improvised weapons, escape and evasion, de-escalation techniques etc. This type of training has served us quite well.
So it all boils down to the venue and goals of your training as to which training methodology works best.