I asked Claude - it did a pretty good job here:
The Shanahan/McVay offensive system and the McDaniels system have some distinct philosophical and schematic differences:
Shanahan/McVay System:
- Built around an elite outside zone running game that uses specific blocking techniques and requires athletic linemen who can move laterally
- Heavy use of play-action passes and bootlegs that flow directly from the running game, creating easier reads for the quarterback
- Extensive use of pre-snap motion and shifts to diagnose defense and create favorable matchups
- Emphasizes "marriage of run and pass" where running plays and passes look identical at the start, making it harder for defenses to read
- Often uses condensed formations (receivers lined up closer to offensive line) to help with blocking and create more space for receivers to work
McDaniels System (derived from the Erhardt-Perkins system):
- More varied in run scheme approach, mixing power, gap, and zone concepts rather than focusing primarily on outside zone
- Greater emphasis on option routes where receivers adjust their routes based on coverage
- More complex passing concepts that put more responsibility on the quarterback to make multiple reads
- Less reliant on play-action, though still uses it
- More spread concepts and empty formations (no running backs in backfield)
- Terminology is concept-based rather than play-based, allowing for quicker adjustments
The Shanahan/McVay system is generally considered more "quarterback friendly" as it creates clearer reads and more defined throwing lanes, while the McDaniels system typically requires more from the quarterback pre and post-snap but potentially offers more flexibility in attacking defenses.