Although I have only a few data points, I think I have some proof to show that ETF ranking does drive short term return, barring any fundamental changes.
For the week starting on May 9th, my ETF ranking put XLB slightly above XLE. And for the first two day of that week, XLB rose 2.31%, slightly higher than the 2.23% rise of XLE. But then both reversed their courses in the rest of the week. By Friday, XLB was down 1.78% for the week, a bigger one than the 1.35% drop of XLE for the week. My guess is that fundamentals deteriorated in materials sector duing that three days so XLB was down more severely for the week. Actually, if you pay attention to this week's Sector ETF ranking article, you'll find that we did see fundamentals deterioration in materials sector in the week before.
The same happened for the first two days of this week. My ETF ranking put XLE slightly above XLB for this week. By today's close, XLE is down 0.76% for the week, relatively better than the 1.53% drop of XLB. As the earnings season is approaching to its end, hopefully we won't see any fundamental changes for the rest of the week. And hopefully XLE will continue to outperform XLB in near future.