Just remind yourself it is only a game. It honestly does not matter if you lose a match or race or whatever.
Everybody loses at some point. It happens. When you lose just say so be it, maybe next match I'll win.
Don't take the game so seriously. There are times when it's appropriate to get mad and there are times when it's not. If someone is spawn camping you in a FPS, that is ok to get mad about, but losing match in general is not.
Don't play. Don't lose. Don't touch anything multiplayer related. Those are the only ways that I don't get frustrated. But frustration is part of life and it's part of the experience of gaming. So I just deal with it and try my hardest to breathe or walk away when I'm getting too upset.
I hate that "It's only a game" remark. Everyone seems to be preaching it, yet people still get angry.
Don't play games that make you angry. Simple. Once they make you angry, stop.
It's much easier to become enraged at Call of Duty than it is compared to games like Solitaire or Bejeweled.
Don't play intense games if they upset you. Try to find a balance between that and relaxing.
My recommendation would be to reflect on what happened and see where you went wrong. After you do so, drop it as it's in the past and take a short break before trying again.
*If playing an online game, look for constructive criticism from others (if there's any) to see if you can improve your current skill. If it's just rubbish feedback, ignore it as they have no sense of sportsmanship.
參考: -Serious gamer since 2007 :D
My best advice? Breathe. I hate to play the "it's just a game" card but...It honestly is. If you want to work on skill practice isn't the only thing you need to do. Research is essential in getting better; Study the wiki(Assuming there is one), watch top players via streaming or spectating (What are they doing that differs from you? What can you learn and/or emulate from this?), find a guide or someone willing to coach you.
tl;dr version: Turn that anger mindset into a "How can I do better?" mindset.
Control your anger, it's the simplest way. I have a HUUGE problem with anger in Black Ops 2 (Call of Duty), it infuriates me so much, although I love the game.. Now I started Battlefield 4 and instead it infuriating me, whenever I die, I don't really care, sometimes a laugh because it WAS funny, sometimes I groan a bit because i jist reached this and that place. Just for some weird reason, anger is not triggered when playing that game, because I simply have no reason to be mad for, there is no point of being mad, it's a weird thing my brain does with different games.. In conclusion, anger management is the key, if you can't stand the game, switch to some other game you love, or in other cases, just switch off your device and do something else that is calming :D
I have played many live multiplayer games and I would get very mad every match. The games would effect my temper and even when I wasnt playing video games I would get mad or over-react to small things. I suggest either to play only one or two matches day.
Pretty easy to do so in a live multiplayer contest, but just a regular computer?
Well, what I used to do is get a Game Genie or some other cheat... then laugh at the game and point at the screen, when it couldn't beat me anymore... but that's a bit of a complex.
Ah a thing that used to happen to me when I was young, but honestly Meditation has been the best cure of anything stress related and I have a 2 year old and 3 year old nephews that I take care of for about 10-12 hours a day, and an I'll mom that I take care of as well it gets stressful but meditation takes it all away. (^_^)