The three major grading companies are PSA, BGS (Beckett), and CGC, and all three grade on a 10-point scale that looks at centering, corners, edges, and surface
Literally everything
One of the most anticipated cards from the set is also one of the most valuable, boasting memorable artwork coupled with an insane 6/5 stat combo on a card that also forces your opponent to discard while enabling you to draw is pretty incredible to say the least
60 cards, 15 card sideboard, best-of-three, etc
While the market has cooled somewhat from its 2021 peak, Pokemon cards remain highly collectible with strong demand for vintage cards, graded specimens, and modern chase cards
I recommend that every tournament player learn the exact details of the entire combat phase and how priority passes back and forth between players