Short answer: They can't win.
But winning is based on game-journalists prerequisites for winning. Is it based on sheer cheering form the crowd at the press conferences, is it a dazzling-meter of what they can showcase of surprises at their press conference. Is it a mater of how many unexpected surprises they can show, for instance price of the console.
It depends on the prerequisites.

In my opinion, it comes down to how I as a consumer can be dazzled and at the same time be won over.

Right now, there is nothing really that they would have in store, that would turn me into an xbox gamer. I predict they only will have first-party exclusives, and not many of them in the time ahead. Every developer and publisher needs to be at least on the PS4, from a commercial and business perspective, who does'nt want to earn profits from their games on an install base of 60+ million consoles.

They can only win votes for better hardware specs, and perhaps price. But I doubt the price will be lower than 499.

The key for Sony is that they have Japan and right now Japan is producing hits. Sony doesn't have to do anything to get those games exclusive on their system and MS has to move the Sun and Moon to get them on theirs. There is nothing MS can do this gen to turn those tables around. MS would need to be able to get exclusive PC content on their system to even notch Sony at this point. E3 will not make or break MS as I believe they will have a solid conference but this gen is over. Sony will remain the run away favorite for the next 3 to 4 years before the next system drops. Once that happen, MS, Sony and Nintendo will have a chance again to either succeed for screw up.

No it's not when the demo of Scalebound was first shown it didn't really impress and it was delayed, I don't think that ever happened to Alan Wake.

It was a Platinum game, of course there was interest in it. After Gears 4 was released, Scalebound became the most anticipated XBox One exclusive by far. There is no doubt about that.

Of course they can. They have new hardware and they seem confident in the run up to this E3. I think they will have a lot of 3rd party games showing off the Scorpio that will take up a good chunk of the show but I think they also have a few surprises in terms of exclusives. Looking forward to 10pm BST!!!

Good, some positivity. We will soon see their conference but so far there been some good news. 199 XBO S and 9GB available for games on the Scorpio. Of course it will come down to the games and hopefully Microsoft doesn't pull an EA conference. I'm more excited than I thought.

realistically, i don't think they can in most people's eyes

when i read people saying they expect MS to announce a ton of games alongside Scorpio, I always think, games from where?

Win against the other 2 or win among all? If against the other two, then the other two have to suck (think Sony just shows GOW, Days Gone, smaller games and that's it, Nintendo just shows Mario). If among all, impossible cause Bethesda already has TEW and Wolfenstein. See in point in Scorpio, just like PS4 Pro. After spending hundreds of hours playing Nier Automata + Persona 5 then getting bored to death after 6 hours of Horizon ZD all i can say is why have new hardware when the current one is already being wasted

Was there even a need for current gen when Persona 5 works just fine on the PS3? ;D

Releasing Zelda and CIV7.