The Astros are fourth in the RPI and first in the Pythagorean (right most column). ESPN RPI I do not know if that proves anything except they win big and lose the close ones. What can you do about that? I guess just win all your games.
This is nothing new... they would have ran away with the NL last year, based on their pythagorean numbers. In fact, its somewhat become a trademark of Jimy-run teams to have such a great pythagorean number, but still come up way short in the real W-L number. I don't see anything that wrong with it... especially since they've already had several games this year where they didn't play their typical "feast or famine" ball... including four out of the last five games.
Obviously, the Astros Pythagorean record is going to be higher after absolutely clobbering pitching in some early games. But since then, there has been signs of the offense returning to normal levels. It's still really way too early in the season to draw conclusions. The sample size is just too small.