>>105858851I think Strange knew Thanos HAD to win but it had to be very close to make Thanos worry on the next attempt they make. That's why he calmly hands over the stone, because Peter Quill has done his part freeing him.
Thanos is so strong you can't beat him in a straight fight, and the infinity gauntlet takes him to a whole other level, but Thanos' one weakness is his mind. He's not all-knowing nor all-seeing, so making him think he's won means that he will be more passive.
Watch as the big reveal is Strange explaining step by step what he did to push every event after into perfect alignment to fix everything.
Maybe the snap happening, causing Antman to be stuck in a subatomic space is good because he's alone now and has to figure it all out for himself the true technique of it, which in turn they are able to exploit to travel through space/time to save Tony and the others. (Maybe Hank Pym would have been too reluctant to help)
I dunno. But I think saving Tony Stark was the most important move of all.
