Can someone explain this to me about brushless esc's
 

I have been doing a lot of reading about the differences on the delta and wye configurations in brushless motors, I am confused. On delta config, all three phases fire at varying levels, on wye config, only two phases are fired. How does the esc understand and adapt to this? It would seem that you would need different programming for both. In all my reading, I never read how the esc reads and adapts to the differences. Thanks for any answers

Sort of.

When you fire a D motor, you are energizing all three coils really; one coil in parallel with the other two coils in series.

When you fire a Y motor, you are energizing two coils, in series, simultaneously. And one is left unenergized.

Yeah, that's different, but there are still only three points to fire off total, two of which are fired at any one time. Why would there need to be different programming?

From where i am looking, it seems both are so different. you have a series on one hand and a series/parallel on the other. Maybe they aren't as different as they appear, but they seem so opposite. Maybe my lack of tech knowledge is causing it. I am trying to understand how it works.

Well, that is the reason why the kv of a delta is 1.73X more than a Y kv for the same wind count. The efficiency increase in the Y is probably attributed to the "dangling" coil end (as opposed to all three coils being energized somewhat in a D motor).