I use a 24/7 Sports Composite Rating of 87.5 and up to distinguish "Blue Chip" recruits. That rating generally corresponds with the top 15% of all recruits and a rating in that range usually means that at least one service has rated the player as a 4-star.
In the five cycles since Petersen took over, the Huskies have closed on 16 of 24 (67%).
During the illustrious reign (5 recruiting cycles) of mythical recruiting god Steve Sarkisian, the Huskies received commitments from 10 of the 22 players (shit %) that were rated that high from the state of Washington.
But wait, there's more.
Of those that didn't sign with the UW under Petersen, I know that Dontae Powell (JC), Rypien (Spoklefuck), and Harrison (Garfield) did not have commitable offers.
On the the topic of how darn hard everything is...
The University of Washington recruits the bulk of its players from further away from home than any other team in the Pac-12 not named Stanford. It is also #2 among ALL Power 5 programs. WSU is just a whisker behind on that metric, but are clearly doing so much less successfully, as judged by recruiting rankings and results on the field.