I think it's an unofficial un-corrupted from of competition. You do it to train but it's not like they ain't really going, right?
Oh yeah, they're going. But different sparring partners are there to give you certain looks. If I'm a welterweight and I bring in a middleweight to give me some in fighting reps or get used to that weight leaning on you, it would be wrong if I go and brag that I gave a middleweight some work when he's there for a certain look....he literally paid to provide a certain service. There's even more nuance like Floyd fresh outta jail or Paulie being fresh off the couch. There's even more nuance when you're literally working on things like setting traps or working on getting outta the corner. So if someone comes in the gym and see you laying on the ropes or constantly working yourself outta the corner, it may seem like you're getting worked when all you're doing is practicing. Don't get me wrong, some sparring is just machismo sessions and you can come away with a feeling someone got the better of someone in that session, but it's hard to stand firm on the "so and so gave someone the beats" in sparring. That's why most fighter's shy away from bragging on it cause they know the different context sparring comes with. Otherwise, there would be a bunch of 9-0 prospects sticking their chest out cause they gave a world champ fresh off of a year layoff the beats the first weeks of their camp simply because their conditioning was ass.