Rufous

With some offensive positions, the number of each player type on the field can vary. There can be one, two or even five wide receivers on the field, but there must always be five offensive linemen. From the quarterback’s point of view, those five are: the left tackle, left guard, center, right guard and right tackle.
The center is the most important member of the offensive line, said Oben.
“Every single play, the center touches the ball,” he said. That isn’t true for any other position on the field. When a play starts, the center snaps the ball, handing it or tossing it between his legs to the quarterback or another player. This starts the play.
The center is often the captain of the offensive line, said Andy Ryland, senior manager of education and training for USA Football.
“[The center is] responsible for a lot of the communication and inter-play play calling,” he said. What that means is that when the team gets ready for a play to start, the center may look at the defense and make adjustments to the way the line will block (in other words, which of the other team’s players to stop from tackling the quarterback or running back).
After the center snaps the ball, the offensive line is usually not allowed to touch the ball again, unless a pass is tipped or the ball is fumbled (Note: A “fumble” is when a player carrying the ball drops it). Instead, the linemen either act as bulldozers, pushing the defense out of the way on a running play, or protectors, forming a circle — or “pocket” — around the quarterback to keep the defense away from him, said Ryland.
“[Offensive lineman] are the ultimate teammates,” Ryland said, because their job is to make their teammates succeed. By blocking the defense, the offensive line makes it possible for the running back to gain yards or the quarterback to make a touchdown pass.