Playbooks

HB Belly Weak out of Singleback Ace Overload is a power run play that sends the HB on a slight delay to the weak side, letting the play side guard and tackle create a double team push at the point of attack before a puller kicks out the edge defender. This is a downhill, gap scheme run designed to beat light boxes and undisciplined run fits rather than a coverage shell. The primary read progression is backside cutback first (if the backside defender crashes down), then the play side B gap, then bounce outside if the edge is sealed.
Watch linebacker depth pre-snap, if they are stacked tight to the line in a 4-3 or 3-4 base front expecting run, this play can still work because of the double team at the point of attack but the cutback lane may close fast. Identify safety alignment, if both safeties are deep in a two high shell there is likely a lighter box and this run scheme will hit harder. Key the play side defensive end and outside linebacker, if they scrape hard to string it out, look to cut the run back against the grain since backside pursuit is the counter to this power look. Beware defenses showing a heavy blitz package or overload front to the play side, extra defenders in the B and C gap can beat the blocking scheme before the double team forms. Sniff out user controlled defenders sitting in the hole (spy or lurk technique), a smart human defender reading the guard pull will jump the play side gap immediately, so have the cutback read ready.
Check the box count before the snap and only run this into 6 or fewer defenders in the box for the best odds of a clean gap. Use play action off this look later in the series (PA Belly Shot or PA Misdirection) once you have shown HB Belly Weak a few times, since linebackers will start flowing hard to the play side. Manually control the fullback or lead blocker if the game allows it so you can steer the kick out block onto the most dangerous edge defender. Pair this play with HB Stretch and HB Misdirection in the same personnel group to keep linebackers guessing between zone stretch, misdirection counter, and downhill power. Run this on early downs (first and ten or second and short) when defenses are more likely to sit in base fronts instead of nickel or dime sub packages.