Different teams because of speciality of position and conditioning

You need to be extremely fit to play unless you think sprinters don't need to be in good shape.

One on one tackling skill sucks.

There isn't a lot to do post HS if you aren't playing in college.

You need to be roughly 21 to play in the NFL so straight from HS isn't possible unless you sit out three years

Don't want to fumble

- why do they have a defensive and offensive team, why not just one team. Do you get players playing both positions?
Specialists emerged over time; back when the game started and into the 50's and 60's players would go two ways, but with huge rosters (NFL teams have active rosters of 53 players) they don't need 'jack of all trades', they need people who do one thing great.

- there seems to a reasonable amount of focus on conditioning, yet it's a very anaerobic sport, you don't need to be fit do you?
Players are fit for what they do...inemen are huge and powerful, think sumo, so they're not 'fit' in the sense of running a marathon but they're needed for quick bursts of power. The rest of the positions, their conditioning is based on being stronger and faster than their opposition; the game might not require them to be in incredible physical shape but they are because their opponents are. That said these players have max efforts of 5-10 seconds ten or fifteen times on a drive, for 8-12 drives a games; to do that at the top of your sport you ahve to be in incredible shape. As the first response said, think of sprinters and the shape they're in. Now think of a wide receiver: they're sprinting (in some fashion) over and over, and need to catch, avoid tackles, block, sometimes tackle...the game is incredibly physically demanding and NFL players are among the best athletes in the country.

- playing and watching rugby my whole life, the one on one tackling seems very poor, a player gets within reach of the guy with the ball but is unable to get him down. Is this something that is raised? Top level players in rugby missing basic tackles like that would probably be benched
This is likely a product of poor tackling mechanics taught at the younger levels. Kids start out in football with the pads you see on NFL players, big helmets and shoulder pads. When you're wearing that gear you 1. can't move as well, as a kid it's hard to learn form when you're just trying to get a grasp on someone; and 2. feel indestructible, and a lot of proper tackling form is understanding your own vulnerability--protecting your head, staying low and driving.

- what happens to the high school football players that don't get to college, are there non-college football leagues out there? Social leagues etc?
There are but not like many other sports here, where senior leagues are real popular (hockey around me in the northeast is big, but also softball, basketball and soccer). Most of the senior leagues I know of are 'flag' football - non-tackle version that's usually 7v7.

- do you have to go to college to get into the NFL? Can you get in straight from high school?
You have to attend college, and the guidelines are fairly rigid (amendment: you have to be 3 years removed from HS graduation). Part of that is the power of the NCAA in controlling the sport for those college years, but part of that is boys vs men...the NFL game is insanely fast and dangerous, even the best HS kids need a few years maturing before they could handle the NFL game. And unlike the other major US sports there isn't a 'minor league' for the NFL, so once you're drafted you either make the roster or you don't; teams have something called a practice squad, which acts as a holding ground for some players who aren't quite ready, but there's no good way to learn the game and grow and mature unless you're on a college team.

- why don't they pass after the initial pass from the QB? Obviously they don't want to fumble, but I was watching one game, the running back had run 50 yards, he was going to make the first down near the opposition line, knew he was going to be tackled, but had a man outside him, he could easily have passed him the ball and a TD. Some of these running backs have incredible ball handling skills, so surprised they don't pass a bit more.
The ball starts at the line of scrimmage; teams are allowed one forward pass (typically the QB makes that pass) and it must be behind that line. Once the ball passes that line the only 'pass' allowed is a lateral, no forward progress. These are obviously risky, and time and again you see players attempt them and it results in a turnover. And that's the big, big difference between football and rugby: a 'turnover' in rugby is a fluid thing, happens many times in a match. In the NFL possession is paramount, you do all you can to avoid turnovers because it's such a precise game these days, stats show that the team losing the turnover battle generally lose the game. If you turn the ball over 5 times in an NFL game there's a very, very good chance you lose that game. I do think it'd be fun to see a team institute more laterals into their plan, but over and over you see wrinkles like that die quickly because they just don't work.

I had no idea college attendance was mandatory for going into the NFL.

I wonder if some of the tackling difference is due to the pads. I played backyard football with adults for a time when I was in high school, so essentially rugby as far as padding goes. You can not as the person with the ball or the tackler throw yourself into someone the way you do in football.

Yeah but repeated anaerobic efforts are heavily influenced by aerobic ability because recovery is aerobic and as you do multiple efforts aerobic metabolism increasingly contributes energy even during the effort.

If you don't go to the NFL you spend the rest of your life boring everyone around you with meaningless and uninteresting tales of your glory days of pigskin in high school. You are usually resented in your community for this. Your boss hates you for it but keeps you around because you desire to find the glory you last had at 18 drives you to be a moderate employee. You follow high school football even though your kid doesn't play. You convince yourself it's not creepy. You are buried with your class ring and your final words are, "It was 30 seconds left in state. The coach called timeout and waved me in to the sideline, "The whole team is depending on you..."

I remember scoring four touchdowns for Polk High in the state championship. It was glorious.

That's good.

I updated my post, you don't have to go to college, you simply have to be three years removed from HS graduation. But in those three years you have to have shown NFL teams you're worthy of a camp invite. Arena league, some foreign league, sometimes a rugby or soccer player will get an invite as a kicker or gunner. So it's not 'you have to attend college', but without any junior programs, minor leagues or indy leagues you basically do need to go to college.

Totally because of the pads, I was trying to get that across in my post. When you're a kid, learning the game, you have that big helmet and huge shoulder pads trying to tackle other kids with the same gear. It's like wearing those sumo suits trying to tackle. It's really hard to learn proper form and wrapping up when you can't even raise your arms above your shoulders, so kids often resort to shoulder tackles.

Class rings have got to be one of the biggest scams going. I don't know if kids still get them but I remember when I was in high school it was such a big deal to get one. When I see an adult with one on, for reasons I'm not entirely sure of, they go way down in my estimation.

They sell shoes......

You don't need to go to college you just have to wait three years after you graduate

Well played Al.

I think some of it is pads but mostly helmet. The pads are a minor part they would still try to kill each other tackling. Some of the pads the pro hockey players wear are only there because they have to have them. They are irrelevant from a protection perspective and they still try to run over each other.

Too risky I think. A bird in the hand, so to speak. Lateral, or backwards laterals, are legal but too risky. Players are fairly conditioned not to "improvise" too much. Execute the play as it's drawn up.

My $0.02 - hope that helps.

Frank

That's interesting.

If you want Jarryd Hayne (rugby player) in this clip, you can see how easily he hands off the defender at 1.50, poor technique. So yeah I'm guessing getting a rugby coach in will help.

Cool, thanks for the detailed reply.