Your wingers want the ball but it seems to get trapped with the centres. There are three reasons for this other than greedy players or the defence coming up fast and even sometimes offside.
When players stand closer together the ball is likely to reach the winger. However, the deeper the back line is and the farther the winger is from the gain line, he is almost certain to meet a line of defenders.
1. Run hard-pass not run-run-pass
After receiving the ball in the line, the player must run first before passing otherwise the defence is not engaged. Ideally, he runs up the field, not across it, though he can run a little sideways to help pass the ball more effectively.
However, quite often, inside players, like 10 and 12, think they need to bring the ball right up to the defence before passing. This simply closes down the space between defence and attack for the outside players.
The ball carrier should run hard onto the pass, take a few steps and then pass. This should do enough to hold the defence so there is enough time for the players on the outside.
2. Catch-pass hard not catch-gather pass soft
Another reason why inside players hold the ball for longer than they need to is that they catch and then gather the ball. In other words, their catch is poor, they must adjust the ball in their hands to be able to pass it on.
It is a mistake to think they have catch and pass in one movement. That is more appropriate for tight situations where a quick pass is used in a 3v2.
The catcher should take the ball early with his hands “active”. That means hands with palms out towards the passer and fingers bent. This keeps the ball off the chest.
The elbows should be bent so they can take the pace off the incoming pass and then wind up to pass hard to the target. Remember that the target is in front of the next player.
3. The squeeze-depth formula
If your winger stands 30m from the gain line, and the 10, 12, 13 and 15 take a diagonal line from that point, the ball will probably reach the winger. However, it is unlikely the back line will engage the defence and the winger will have to beat several defenders who have drifted over.
The squeeze-depth formula is the sense that the closer the players stand together, the quicker the passes and the less depth they need. So, if you want to get the ball to your winger without going deep (or your players finding it hard to get their depth and timing right), then get them to stand closer together.
As they improve running, passing skills and catch/passing skills, they can move wider apart.
LEFT-RIGHT BIAS
Most players are right-handed and therefore find it easier to pass from right to left. The left-winger is always more likely to receive a pass than the right-winger.
Your players have to be careful not to use too many miss passes to get the ball to this player because the opposition will simply shift with a long pass if it's too deep.
The poor right-winger can still receive their fair share of ball in open play if the team use the three ideas from above. However, the passers have to push the ball harder in the pass. In training, you should listen out for a slap of the ball in the receiver's hands to know that they have passed it hard enough. This is not a time for sympathetic short passes.
CREATE THREATS
Another solution to use is the 10 or 12 attacking the defensive line, then running across in front of the defence but pushing out a pass to miss the centres and/or full back.
They might use a short dummy pass or even a dummy switch. Again, the three ideas from above still hold, but does reduce the number of passes involved.
This type of move works best if there's been a short play in a previous move. For example, a short pass to 12, or a switch pass between 10 and 12. Your players need to manipulate the defence's minds throughout the game by probing them in area first and then threatening to do it again. That threat will hold defenders and create space for your winger.
DO...
Run hard onto the pass then release the ball. That fixes defenders early.
DON’T...
Take the ball right up to a defender then pass. That passes on the pressure.