When I started out, I was under the impression that proper training meant going full out in sparring all the time, trying to emulate a fight as close as possible. In the end, I logged only a couple of minutes of sparring each week with a lot of injuries to show for it. Even when we'd try to "hold back" or "only go 50%" it would inevitably result in the same disproportionate ring time to injury to benefit ratio. (not to mention quickly escalate into full contact sparring)
Years later, I started training with "Luck" Chanon Sinsub- a Thai boxer with about 400 pro fights and 3 national titles. I was surprised at the incredibly gentle way he sparred. In fact he called it "playing". Luck was a genius at teaching the art of fighting without damaging his students before a fight. When you consider his history, it makes perfect sense. He had been competing in Muay Thai since he was 5 years old- often with a pro fight either every week or every other week. That's more ring time from fights than most western fighters log in sparring. So it's no wonder that the sparring in the gym is all about position and technique instead of who can do more damage to the other guy. Just like this article says, you don't get paid to take damage in the gym (unless you're a professional sparring partner)
One of my boxing coaches, Jason Chen, taught me a similar lesson. For the first several weeks, training consisted of shadow boxing and non-contact sparring. At first it felt like a huge waste of time because no punches were landing, but I payed attention, and I learned my lessons. For the next few months, it was light contact sparring with very restrictive rules. We never went full out. We never tried to KO each other, "rock" each other, or even cause damage. It was all about position and technique. In the end, it made a world of difference. Watching footage of me in the ring today compared to 6 years ago is night and day.
The guys who try to be monsters in sparring all the time look awesome for a while, but ultimately, they have very short careers, and they're a huge risk to the longevity of their training partners.
MMA in China is still in it's infancy and grappling is still a pretty new thing, but they have a long history of good striking. So it's fascinating to see firsthand the difference in striking skill among American MMA fighters and their Asian counterparts. Off the top of my head, I can think of maybe 5 or 6 guys in the UFC who are good boxers. There are plenty of MMA fighters who throw lots of heavy punches and score knockouts, but not too many of them are 'good' boxers.
Most of the American MMA gyms I've been too divided their training time like this: 80% BJJ based submission grappling, 20% striking, takedowns, wrestling, conditioning, and everything else. Most of the sparring they do is heavy and dangerous. And that's a fantastic formula for creating fighters who not only don't know how to box, but don't know how to use strikes to spar safely and effectively for mixed martial arts.
In China, it's basically the opposite. First there are very few MMA specific gyms (When I first got here there were none) At Chinese combat sports gyms, striking is always the major emphasis, particularly boxing. As a result, you end up with lots of fighters who can handle striking beautifully, but are basically fish out of water on the ground. Most of the sparring they do is low key and light contact, but they do a lot of it- as in three hour long sessions a day every day on top of technique and conditioning. The western all-out mentality would kill fighters here before they ever stepped in the ring.
Likewise, if you asked most American fighters to log 3 hours of sparring a day, they would never make it through the first session let alone the first day because of all the cumulative damage.
Safe & effective sparring is a skill set that every serious fighter needs to learn.