Yeah, well, that is all good and everything but what do captains really do? I really don't know.
It is more ceremonial than anything
NFL rule 18 details the guidelines for team captains. Within Rule 18, there are four articles that pertain to:
- Number of Team Captains
- Coin Toss Procedures
- Choice on Penalty Option
- Change of [Team] Captains
Coin Toss Procedures – Each team can send as many as six team captains to the center of the field. On each team, one captain is designated the "speaking captain" of the delegation. The visiting team or the team designated "visitor" by the referee (if no team is declared 'visitor') shall choose "heads or tails" or in the case of a special ceremony coin, the options on the face and rear of that coin.
The winner of the coin toss have three options, 1. Defer the choice to the second half, 2. Receive/kick the ball, 3. Choose an end zone to defend. There is strategy in employing your election. It could depend on such conditions as weather, or making an aggressive statement at the beginning of the game, or something simple as coming out of the locker room in the second half receiving the ball.
After the winning captain makes their choice, the opposing team captain chooses from the remaining two options.
Choice on Penalty Option(s) – The offended team captain has a choice of accepting a penalty enforcement or declining, except where said penalty is automatically "enforced by rule." In some circumstances, a team captain may elect to "decline" the penalty. This typically happens in a situation in which declining the penalty may mean that the next down should occur (3rd or 4th). A good example would be on an "offensive holding" enforcement, the defensive team might elect a "4th down and 5 yards to gain" v. a "3rd down and 15 yards to gain."
https://en.wikipedia.org/wiki/National_Football_League_team_captains