Why was Bill Belichick throwing a blocking pad at Tom Brady?

FOXBOROUGH, Mass. -- New England Patriots coach Bill Belichick is as hands-on as they come, often inserting himself into drills and providing one-on-one instruction. Every now and then, he'll start throwing things at his quarterbacks, too.

That's what unfolded Tuesday morning when Belichick wound up with his right hand and fired a blocking pad at Tom Brady in a video that garnered quite a bit of attention. It was a pretty aggressive toss from the 65-year-old Belichick.

Left a bit unaccounted for was the purpose of Belichick's act. No, he wasn't just taking out some frustration on Brady. He was trying to make him better.

The drill, which is commonplace in the early part of Patriots practices in position breakdowns, is designed to test a quarterback's ability to feel the pass rush -- and react to it -- without looking at it. So in this case, the blocking pad was essentially a pass-rusher, and Brady had to react while keeping his eyes down the field at the coverage.

Patriots coaches have a similar drill that forces quarterbacks to test their ability to make throws -- or run -- when moved off their original spot. In those drills, the quarterbacks are hit continuously with longer blocking pads.

From last season: