Playbooks

HB Power out of Shotgun Bunch Y-Flex is a gap scheme power run that pulls the backside guard through the hole while the offensive line downblocks to create a lane on the strongside. The HB takes the handoff and presses the play side hole, reading the pulling guard's kick out block on the edge defender before deciding to bend it inside or bounce it outside. This is a pure run play with no route combo to speak of, so the primary read progression is simply blocking surface first (has the double team sealed the interior), then the puller's block, then daylight.
Pre-snap, count the box defenders and check safety depth, if a safety is sitting at 8 yards or less he is likely in run support and will fill the alley fast. Watch the strongside defensive end and outside linebacker alignment, if they are crashing hard down inside the pulling guard will have a clean kick out angle. Post-snap, key the play side linebacker's first step, if he flows hard downhill without hesitation the cutback lane behind the puller will open up. This run gets shut down by disciplined gap sound defenses that keep linebackers square and stack the box with an extra defender off an edge blitz. User controlled defenders spying the pulling guard or crashing down the line of scrimmage from depth are the biggest threat to blow this play up before it develops.
Run this on early downs or short yardage when you need a physical, downhill gap scheme to control tempo and set up play-action later. Check the box count pre-snap. If the defense has 6 or fewer in the box this play has a numbers advantage, if you see 7 or 8 in the box consider audibling to a passing concept instead. Use motion or a hard count to bait linebackers into flowing early, which opens up the backside cutback lane for the HB. Pair this with PA Post Y-Corner or PA Post X-corner from the same set later in the drive since the play-action look off Power freezes linebackers who have been conditioned to bite on the run fake. Against aggressive nano blitz packages, trust the pulling guard to clean up the first wave and get the HB moving downhill quickly rather than dancing behind the line.