I recently just broke a old habit of mine which was looking at the scoreboard constantly. I did this when I was around bronze and was always looking at the K/D board to see how good or bad I'm doing. However, I stopped and I was able to get to silver and gold.

Reasons why to do it:

1. literally just help you with mental. If you're doing bad, you will be deterred by your score and just do bad. If you're doing good, you will become egotistical and go for ego peeks and just die.
2. The scoreboard lowers your fps, if you have a bad pc like I do, lowering you fps will screw your reaction time up. So if someone just peeks you while looking at your scoreboard, you'll most likely not be focused and not able to react fast enough.

Thanks for reading!

TL&DR: don't look at scoreboard if you're having issues with mental confidence and fps mid round.