One constantly reads in biographies about Gedolim or at a friend's siyum HaShas that mention how the talmid chacham or guy is a bucky and a maeivin in Shas and poskim. See example in this Wikipedia article about HaRav Refael Ahron Ben Shimon, in the first few sentences: בן שמעון נולד ברבאט שבמרוקו, לאביו הרב דוד בן שמעון ולאמו רחל. בשנת 1854 עלה לארץ ישראל ביחד עם אביו. בילדותו קיבל חינוך מסורתי והצטיין בידיעותיו בתלמוד ופוסקים.
What does it mean to be bucky in Shas and poskim? Does it include knowing the:
Klallim and concepts?
Interconnected sugyot from different mesachtos?
Basic shakal v'taraya on every amud baal peh, as in knowing every word verbatim as mentioned to being a "Shas Yid?"
What is the geder of "poskim?"
4a. Does this include knowing all the mefarshim: Rashi, Tosfos, Rishonim, Achronim all the way to halacha l'maaseh in modern poskim?
4b. Does that also mean Baal Peh or the general concepts?
4c. What about the different variations of how you can read and interpret (bavern) the concepts? Is part of being a bucky in that regard include knowing the variations word-for-word or just conceptual memorization suffices?
4d. Which poskim do we refer to? Rambam, Rif, Rosh?
4e. Do we include Tur, Shulchan Aruch, and all of their mefarshim/Nosei Kelim?
4f. What about modern Poskim and Shu"t of different Rabanim?
4g. Is it all of the above?
What does it mean when one says that he "knows Shas and poskim?" I know that each Jew has a different part in Torah, and assume that the level of an average but hardworking 21-year-old bachur who just finished Shas isn't going to be the same as Saar HaTorah, Rabbi Chaim Kanievsky. Even with the understanding that each Jew has a different chelek and level in Torah, it still seems unclear what is included in this bukiyus?
Still, there seems to be a well-established status quo continuously referred to that is not clear what defines "bucky in Shas and poskim."
Please provide sources for your answers.