I made two misplays that cost me the game...
I was playing Tibor and Lumia vs GW Rhys and UB Sygg. The Sygg player had an insane start with a mox, sol ring, mana crypt turn 1 and was basically dominating the game. I had been mostly mana screwed but was finally starting to stabilize and get back into the game. I was at 7 life and the Rhys player was Sorin'ed to 10 earlier but was gaining some life so he was around 12 at the time with Sygg around 39 due to a Wurmcoil. There was about 30 power on the board with Rhys having ~18 from White Sun's Zenith tokens and Sygg with the Wurmcoil and a few other smaller things. We all knew Sygg was going to win on his turn with an EOT flashback'ed Army of the Damned (Quicken).
I draw for the turn and cast
Act of Treason,
Radiated with a single mountain left untapped. Sygg casts
Doom Blade on the Wurmcoil thinking it would foil my plan but then realized the copies would be created before the spell fizzled so then he
Force of Wills the Radiate. Tapping the last Mountain, I then cast
Ricochet Trap on the Force of Will and redirect it to the Ricochet Trap to make it fizzle. There was my first mistake. Had I redirected it to the Doom Blade, I would have ended up with 13 life rather than 10 so that Rhys could not kill me AND Sygg on his turn and I'd have at least one more turn to recover. I knew I was the lower priority target since I really had no board state of my own and Sygg had been drawing a lot of hate that game. Went to the attack phase and sent all in at Sygg since I wanted to make sure he didn't win, leaving him at 9. That was the second mistake. Had I sent a few at Rhys, he would have had to commit more to killing Sygg and wouldn't have had enough to attck me for lethal as well. On his turn, he cast a Loxodon Warhammer and was just barely able to hit us both for lethal.
I don't recall what my next draw was going to be but I remember it would have been the win for me... Instead of an epic, come from behind victory I had a disappointing defeat. It was still a pretty good game though.