For breakout year I would consider Dickerson. Top 5 at Worlds, top 10 at USDGC, great finishes at Idlewild and PFDO, nice ratings jump (1034 rated now), he did however lack a statement win. Still this year I think he showed he is going to be in the mix for a long time to come.
...and right on cue, Dickerson tied with McBeth and MJ at -18 at Fall Colors (He and MJ both with a 1064 rated round (one of their two) today). Not sure this A Tier has the draw to be considered a statement win, but if he holds on tomorrow would certainly be a nice end to his season.