A common question I get asked is whether you should spar hard or stick to light technical sparring. Now I truly believe that there is a time and place for both types of sparring. For example, if you are in fight camp, it is good to have a few hard sparring sessions to be familiar with what it is like to get hit really hard, as well as get familiar with the pace that a fight can get up to be!
On the other hand, whether you are a professional fighter, amateur competitor or a recreational martial artist, you should dedicate and emphasize light technical sparring! I recommend this type of sparring for obvious reasons, such as, to protect your brain from chronic traumatic encephalopathy(CTE) and to maintain your health for the longevity of the sport. But I also recommend this type of sparring because this is how you develop your skill and how you build confidence to try new techniques that you've learned.
If you are sparring hard with your partner, there is an ego involved and therefore you don't want to lose. You resort to using only your best weapons and you never test out new strategies, techniques, and combos to see if you like them and want to add them to your arsenal. Therefore, you will never evolve as a fighter.
Instead, you should be sparring with a partner you trust, and try out new attacks or counters to see if they fit into your style! Sometimes they don't work or you don't like it, and you discard it. Sometimes they work very well and you love it, THEN you can start trying them in a hard sparring session and see if it works.
I am very lucky to have Randy Turner, who also happens to be a former Canadian Special Forces Soldier and former professional MMA champion, as a training partner. When we spar, he brings out the speed as well as the intensity that resembles a real fight, but at the same time he pulls his punches so that he doesn't do any damage. Because he is someone I trust and respect, I am not scared to try out new techniques and combos on him.