I'd say a blue-chip prospect is something very close to a sure thing, but it is generally used much looser than that around here. As we've seen outside the tier behind McDavid this decade of center prospects like Matthews, Eichel, MacKinnon, and Seguin is probably that next tier of sure things (and before that Stamkos and JT). Now, some hit very high highs like Draisaitl, Barkov (Barkov arguably belongs in the first grouping, but it should be remembered he was viewed closer to Monahan and Lindholm by most at the time of his draft) and Pettersson in that next grouping (just speaking as prospects), but you also get your fair share who end up good players but not the #1 center you expect of high-end prospects (Sam Reinhart, Dylan Strome), some who are productive NHLers but are quite replaceable players (S. Bennett), others who are highly inconsistent (R. Strome, Galchenyuk) and others who are high-end but move positions (Huberdeau and to a lesser extent Lindholm), finally, you got guys like Monahan, PLD, and Hischier who are currently their teams #1 center, but might not be the ideal top 15 center in the league you hope for when drafting high (Hischier and PLD still have time to reach that on a consistent basis, but it remains to be seen what they are).
I'm not sure any of the centers in this draft are locked-in to be elite players like that tier behind McDavid I mentioned. Byfield could reach their level, but has more risk attached in my eyes. Blue-chip by definition is something with very limited risk, but like a lot of terms around here, things get bumped up all the time (for example generational is abused like crazy).
