Luck has no memory. If you roll a 5 on a dice you are as likely (1/6) to do it the next time you roll. Therefore, you would think that win streaks and loss streaks shouldnt happen in MTG. However they do in my opinion. The reason is how it affects your play. When youre winning a lot, you tend to win more and more. And the reverse is also true for losing.

It is because when you are winning you tend to make better decisions. When you are losing however, you tend to make bad decisions and also make some of gthe following:

1) Play too conservatively and scared.

2) Play too reckless and attack to aggressively.

3) Give up too early. Both conceding not yet lost games as well as mentally giving up.

How do we combat the downswings? One thing i like to do is to take a small break from playing. a week or two is usually enough. When you come back you tend to have a fresh clear mind that has been reset and now you are back to making good decisions again.

You can also be proactive and not care about losing as much. This can be easier said than done. One way is too play magic online, If you play on magic online you will lose a lot, simply because you tend to play a lot more. The  more you play, the more you will lose (and win) It like when we combat fear, we expose yourself to the things we fear, and little by little, hopefully the fear goes away.