VIDEO: Kyle Shanahan Gives Fans a Sneak Peek Into His Playbook and it's Insane

The San Francisco 49ers won the NFC in 2019 in large part thanks to the masterful offensive scheming and play-calling of head coach Kyle Shanahan, who earned himself a new six-year contract extension a few days ago. Shanahan gave Mark Schlereth, who played under his father Mike with the Denver Broncos, a glimpse into what makes his offense so difficult to understand, as the amount of moving parts and keys in a basic play call will make your head spin.

That's "Y Short 2 Strong Right Clamp Ace H2 Y Bingo X Comeback Can O Roll Right Z Shallow" for those keeping score at home. Keep in mind, Shanahan expects all of his players to know these plays like the back of their hands.

Some rookie wide receivers struggle replicating the explosiveness they showed in college due to confusion and a lack of familiarity with a pro playbook, and Shanahan's is even more complex than a garden variety NFL offense. Because of this, 49ers wide receiver Kendrick Bourne claims he studies the playbook daily, calling it "no joke."

Shanahan's scheme is a nightmare to digest, but it's proven to be one of the most difficult to gameplan for across the entire league. There's clearly a reason why.