Just a little tidbit of advice from me in my first new discussion, lol.
Basically, I tend to see one of two things quite a lot lately on my teams and both are basically tunnel vision on what they look at for target acquition it looks like.
1.) They probably stare at their radar to look for targets while practically ignoring the main screen. As a result, I see people run out from corners WELL within view of that person, yet that person gets gunned down or knifed with hardly a fight because they were paying minimal attention to the screen and relied solely on the radar to make them appear as a red dot/arrow. Some of those people didn't even have Assassin (Pro) as a Perk either. It was just pure ignorance on that player's part. Only if the persn starts firing from a distance does it catch the player's attention due to the sound, flinching, etc, but it's usually too late when they notice.
2.) They probably stare at the screen to look for targets while practically ignoring the radar like it's totally unreliable. Similar thing. People run around while barely taking a glance at their radar it feels like, even when UAV/AUAV/Recon Drones/etc are used that reveal people's positions, yet they seem to constantly run right into people and die, despite the radar showing them right in front of their position, whether straight ahead, around a corner, the upper/lower floor, etc.
It's either one of those 2 or, similar to the "bad teammate" threads, a bunch of people really are that stupid...
My main point is that people should learn to keep both at attention without giving too much to one or the other as both together are what help you. If you keep your eyes too much on your radar, it's no wonder Assassin (Pro) users are able to get the drop on you easily pretty often. If you keep your eyes too much on your screen, it's no wonder you end up running right into someone's guns that are pointed right at you wherever you come out from, whether it be a camper or another run and gunner. You won't always get very far looking at just one or the other. But keep them balanced out and you'll be more prepared. If you hear someone deployed a UAV/AUAV/Recon Drone or just hear a bunch of gunfire, don't hesitate to take a split second to glance at your radar to see what red dots/arrows appear. Then put your eyes back on the screen and continue on while still taking occasional glances at your radar.
I've had people rage and accuse me of being a camper when it was simply because their red dot/arrow on the radar was clearly heading right towards me (especially if it's real time via Recon Drone), so of course I waited to take him by surprise rather than brashly running out to confront them head-on. Same thing on the flip side; a person using Assassin (Pro) called me a cheater because I saw him coming and was able to kill him rather than him ambushing me when it was because, while he may not have shown up on my radar, I kept my eyes on the screen as well, so he was quite visible to me, lol.
In the end, both your eyes AND your radar should be used in equal fashion. Do this and you shouldn't be caught off-guard so often anymore.