During the NFL draft, fans will be scratching their heads in befuddlement as their favorite team picks a player they have never heard of or who makes absolutely no sense. How do teams ever make these selections?

The NFL draft, along with free agency, is the primary method of roster composition for America's most popular sport. The right selection, in whatever round, can turn out to be the cornerstone of a franchise's success for years, the wrong selection, just a wasted opportunity.

Teams put much thought and millions of dollars into the creation of a scouting system for college talent. Each team has a Director of Player Personnel in charge of College Scouting. There are also a variety of team scouts who are responsible for a geographical region or specific position. They put together a checklist of attributes: Size, speed, strength, athletic ability, agility, character and then head off to spring ball, summer training, and regular season games to judge every potentially draftable player.

They use a numerical system 4-1 with one being highest, or one through ten with ten being highest, to rate players and assign them a numerical grade. They also watch game film and talk with the player's coaches. The second source of input for a team is the scouting reports they use from a pooled scouting company called a combine, which service many teams. Teams can subscribe to "BLESTO" or "The National" and receive the same scouting ratings.

A team will then establish its own draft board, rating players by overall highest grades, then breaking it down by position. These boards are modified by the ever important second season of scouting. Seniors have the opportunity to play in All-Star Games, scouts can interact with players between practices and judge the practices and the game performance.

The major scouting event of the second season is the Scouting Combine held in Indianapolis in February. Players are given strenuous physicals, drug tests and IQ tests. They compete in five drills: A 40-yard dash, 225-pound bench press, vertical leap, broad jump and lateral drills. Teams have the opportunity to evaluate their personality in twenty-minute interviews. Teams have done extensive character and criminal background checks. Players can work out at their position. Ratings on a player will continue to change.

Campus visits in March to Pro Scouting Days allow scouts another opportunity to interact with players and see them do the same combine drills for the first time or another time. The largest single variable in elevating or plummeting a draft pick is speed in the 40. The NFL is speed crazy. And then teams compile their final draft boards with the input of position coaches, head coaches and team executives.

Teams have unique philosophies as to which players fit best in their individual systems. Football is a systemic game where a player can be a major star in one system and a failure in another. The best philosophy in drafting is to choose the best athlete available. Choosing the player from the position a team needs most who is lower rated than another from a position they need less ultimately leads to a less talented roster.

This is why teams who feel the player they covet will be available later will trade down in the draft round and accumulate picks. Teams that fear the player they need will be gone, try and trade up to a position where they can select him. And remember, there is a generalized amnesty on honesty in press interviews a team gives in respect to their intentions–they don’t really want their strategy laid out in public for other teams to take advantage of. So get ready for surprises during these three days of talent acquisition for the greatest show on Earth.

-- Leigh Steinberg has represented many of the most successful athletes and coaches in football, basketball, baseball, hockey, boxing and golf, including the first overall pick in the NFL draft an unprecedented eight times, among more than 60 first-round selections. His clients have included Hall of Fame quarterbacks Steve Young, Troy Aikman and Warren Moon, and he served as the inspiration for the movie "Jerry Maguire." Follow him on Twitter @SteinbergSports.