Each February, hundreds of the very best college football players are invited to the NFL Scouting Combine in Indianapolis, Ind., where executives, coaches, scouts and doctors from all 32 NFL teams conduct an intense, four-day job interview in advance of the NFL Draft. Here is a brief breakdown of the measurable drills:
40-yard dash
The 40-yard dash is the marquee event at the combine. It’s kind of like the 100-meters at the Olympics: It’s all about speed, explosion and watching skilled athletes run great times.

Vertical jump
The vertical jump is all about lower-body explosion and power. The athlete stands flat-footed and they measure his reach.

Broad jump
The broad jump is like being in gym class back in high school. Basically, it is testing an athlete’s lower-body explosion and lower-body strength. The athlete starts out with a stance balanced and then he explodes out as far as he can. It tests explosion and balance, because he has to land without moving.

3 cone drill
The 3 cone drill tests an athlete’s ability to change directions at a high speed. Three cones in an L-shape. He starts from the starting line, goes 5 yards to the first cone and back. Then, he turns, runs around the second cone, runs a weave around the third cone, which is the high point of the L, changes directions, comes back around that second cone and finishes.

Shuttle run
The short shuttle is the first of the cone drills. It is known as the 5-10-5. What it tests is the athlete’s lateral quickness and explosion in short areas. The athlete starts in the three-point stance, explodes out 5 yards to his right, touches the line, goes back 10 yards to his left, left hand touches the line, pivot, and he turns 5 more yards and finishes.

Running Back Skill Drill (Off Tackle Reaction)
For more information visit: http://www.nfl.com/combine/workouts