Having a couple of set plays is always good, but never make them specific to a player.

In juniors, as with seniors, in general, both teams get the same opportunity to make a shot on goal. Each possession is either going to end in a successful shot on goal, un-successful shot on goal, or a turnover. A foul is just a "pause" in that possession. An offensive rebound can be seen as a new possession, or just a "pause". Turnovers can be due to skill error (bad passing, double dribble, travel, out of bounds etc), or a forced error due to good defence.

Obviously a turnover is a failure, so get those under control first.

Shooting % and good shot selection is the key to winning games. If your team is putting up plenty of shots, and not scoring, then they need to work on that between trainings.

Motion offence is good to run and gives every one a chance, but the players need to know the basic rules around it, including spacing, screens, cutting etc. Defensively, players need to know the basic rules as well. Obviously when in defence you want to force a bad shot, or a turnover from the other team.

In U12/14 the key really is skill development, so obviously dribbling (with both hands), passing and shooting is essential. Rebounding (and boxing out) is critical for forwards as rebounding means you end up with even possessions, and defensive pressure is critical for guards as they force turnovers.

As far as set plays are concerned, I think it's good to get a couple of "standard ones". A good end baseline inbounds play is always important as you could be down by 4 and need a couple of quick goals. Same too with a sidelines inbound, sometimes you need a quick goal.

Bottom line, have a few plays up your sleeve for special times, but make sure your team can nail free throws, dribble with both hands, pass accurately, and rebound.

Probably the best summary I've seen about coaching any junior sport by Jack there.
The same discussion happens for AFL. Skills and general play theories (spacing, moving the ball etc) have to be prioritised before all else.
You can have the greatest plays in the world drawn up but if the kids can't execute the basics then it won't get beyond step 2.
For my kids AFL team we work on some structures when kicking in from a behind or the centre bounce but that's as far as it goes. Even then it's pretty basic otherwise they get overwhelmed and confused very quickly.

Agree with Jack, great summary. Some clubs just run firsts and thirds and it doesn't help all the kids (eg, big man just blocks) and can become a little boring and predicable. It’s all about balance at the end of the day.

Flex. Structure & equal opportunity.

Dribble drive setting hard picks to get those corner shooters open.. suffocating full court relentless press
All about dominating inside outside ... destroy other players confidence always sets up future dynasty ...... begin early.
Anti Dev guru...

^ what's all that about? Drivel.

Agree with what Jack said.

5-out pass/cut/replace is good. Develops passing, moving off the ball, spacing, playing in a structure to get players open. And encourages development in all players whether of not they're a "big".

You can add 4out-1 in to add using screens. But try not to earmark your "big" that that is all he or she can do.

Having said that, I did have an offense that I ran with an U14 team. It was taught to me as "UCLA" for a 16s team but others might use it under a different name (over the years I have seen some coaches run a training drill called "Tennessee" and others run the same drill as "Oklahoma" - both full court passing and layup drills!). But my UCLA involved passing, driving, screens and multiple opportunities for all players. However, by it's nature, it could pigeonhole the 5 and maybe even the 1.

As people have said, some set inbounds play. They need these to prevent the "stand around wherever you are when the whistle blows" mentality. And helps develop communication as they have to take responsibility to call the play. Simple box plays that involve screening or stacks.

Hardest thing I found was trying to get kids willing to give up "jungle ball" (just playing one on one, chasing the ball) It is good in social ball because they can have fun and run around. The good players can get away with that in domestic comps but need the skills in rep to deal with good defence, no matter how athletic they are.