Brady is not a difference-maker or a playmaker. He's a product of the system who happens to play the QB position. He needs EVERYTHING to go smoothly for him to have success. As in, his O-Line must protect him extremely well and his receivers need to get wide open.
Brady is a guy who needs plenty of time to make easy decisions and easy throws.
Brady is a guy who needs a perfectly clean/deep pocket to stride into his throws. It is a must that his interior linemen hold their blocks right at the LOS and don't get driven back.
Brady loses ALL his accuracy whenever a defender is bearing down on him. His accuracy under pressure is pathetic.
Brady makes the most boneheaded decisions/mistakes you'll ever see when he's pressured.
Brady cannot avoid the rush up the middle or move laterally. Push the pocket on him and he'll either 1)take the sack, or 2) take 2 steps backwards and throw the ball into the dirt
Brady's ability to throw on the run is completely nonexistant. By far the most inaccurate passer in the NFL when outside of the pocket.