Separation one of the key factors in scouting WRs for Patriots

Revisiting notes by ESPN NFL Insider Field Yates, originally posted in 2012, on how teams scout for players at each position, focusing on safeties:

DESIRED TRAITS: No matter the alignment of a receiver, his physical build or the system he plays in, there are two key aspects to his game: generating separation and catching the football. That may sound oversimplified, but an inability to do so can keep even the most talented receivers off the field.

What goes into separation? A number of factors, starting with a receiver’s release at the line of scrimmage. How a receiver makes his first move against a defender is important to note: Does he win with speed, quickness, his size, leverage, or even his intelligence? Next, how effectively can a receiver run routes? This involves precision, crafty footwork, and the ability to transition his weight in and out of movements.

Ultimately, a receiver’s job is to catch the football, but it isn’t a simple task. A receiver must show he can locate the ball, adjust his frame to put himself in a position to make a catch, corral the front of the football with his hands, and secure it into his body. Beyond that, one must decipher if a receiver has the ability to track footballs thrown outside of his frame (Randy Moss was sensational at this), how tough he is to make catches in traffic (Troy Brown was fearless with defenders around him) and how he reacts in competitive catch situations.

The alignment of a receiver cannot be ignored, either, as that will dictate, to a degree, specific skills a player must have. For slot receivers, quickness and change of direction skills are placed at a premium, while outside receivers usually need to have the ability to stretch the field vertically.

SPECIAL-TEAMS ANGLE: Receivers are sort of a grab bag when it comes to special teams, because you find that some -- like Matthew Slater -- rank among the best on the roster at special teams, while others do not contribute at all on special teams. Bigger, tougher receivers can contribute on core special teams as coverage/hold-up players, while faster receivers are often candidates to return punts and kicks. A typical fourth or fifth receiver on an NFL roster has a major role on special teams.

PATRIOTS TAKE: Julian Edelman, Danny Amendola, Chris Hogan and 2016 fourth-round draft choice Malcolm Mitchell top the depth chart, with Slater locked in as a specialist. If everyone is healthy, that would likely leave one more receiver spot, with Keshawn Martin, Aaron Dobson, Chris Harper, Nate Washington, 2016 seventh-round draft choice Devin Lucien and first-year player DeAndre Carter competing for the role. Both Edelman and Amendola didn't practice in the spring as they come back from offseason surgeries, which means their status as possible PUP candidates bears watching as training camp approaches.