Listen to the class from Sunday morning, "Birkat 'HaNoten LaYa'ef Koah," here.
Follow along with the sources here.
For further research:
1) Read the related chapter from Moshe Hallamish's Hakabbalah here.
2) Read Benny Lau's article, regarding R. Ovadia Yosef's approach to pesak and Shulhan Arukh here.
3) Read R. Ovadia Yosef's analysis in Yabia Omer 2.25 here.
4) Read R. David Yosef's analysis in Ossrot Yosef 3.10 here.