Diagrams are to show that it's one direction then the other direction to increase volume of 1 on 1's.
On Whistle D1/D2 leave with puck and move up to blue line and pass to F1/F2 respectively. F1/F2 attack corresponding D down the outside of center
Next whistle, D start the opposite direction D3 passes to F4 and D4 passes to F3.
Notes: Use for tryouts type scenario