So I've got a bit of a David vs Goliath story for y'all which happened to me all but 30 minutes ago. I think it's worth a read and hopefully you can all take a bit of a lesson away from it
I was playing a solo-que match and was playing Lux in the middle lane. I was against a Diana who is a counter to Lux (post 6 anyway), but with some good mechanics I was winning against her. My team on the other hand though... yeah. They struggled. Their Darius was 12/1/5 and dominated the top lane. The 2 team mates on top both went 0/6/0 and they were struggling big time. (it should also be noted that it was a 2v1 lane as they had a Jungle Warrick, yet they still lost the lane). Soon the team fights started and they took 2 of our middle towers. The Darius started to trash talk, saying stuff like "You all suck, this is over" "your all noobs" "this game is so easy your all useless" etc etc etc.
As soon as he started to trash talk I said to myself "Game on, bitches". It was time to get my A game on. My team was trying to surrender but I told them all that we can win, if we ward correctly and acquire map control than we can pick them off one by one. I convinced the other guys that we could actually win the game, they abandoned the surrender vote, I grouped everyone together and we started to devise some strategies.
With excellent warding we were able to catch the other team off guard and kill them all except Darius. He was still trash talking but it didn't matter. We took 2 of their towers as a result and regrouped. We got a slight advantage back, despite how much he trash talked. The next team fight came soon after and with some good positioning we won that, too! I told everyone to go back, re-buy and stay grouped. They listened politely
So I bought my Death Cap and 5 wards, I was underfed (5/5/10 with 130 farm, the early team fights were rough) but still was doing some good damage. The other team was getting carried away so instead of buying defensive items they bought all offensive items. I knew that if I landed my bindings, our team could focus them down and kill them very quickly.
I warded up Baron/mid lane and told everyone to hide in the bushes. We hid and 2 of them came towards us, with a flurry of attacks they were quickly dispatched. Soon the rest of their team came charging at us but we killed them all, including their Darius, and only took 1 casualty! Their trash talking soon stopped when they found out what was coming next. We quickly pushed down middle lane while they were all dead (I split pushed top :p) and took the Inhibitor! Then a nexus tower! 20 seconds till they revive, we had to push hard! Soon the next Nexus tower went down! Then BOOOOOOOOM! The nexus explodes and we win the game! Victory to TheCuriousCrab and Co!!!!!
Despite their incredible lead and their arrogance, we used our superiour team work and strategy to turn around a game that looked all but lost. To me this is undeniable proof that being arrogant and getting too cocky will always be your down fall. Oh, and it was an incredibly fun game as well!
TL;DR Trash talking loses games
I didn't get a SS of the final score screen, so I got one of my match history instead :p