At d if you cant play physical, you absolutly need speed to defend. If taking 1/2 more to be at your position and your can't play physical. Physical game help you to win some time. I give you an exenple... You're on the rush, you reach blue line, trying to attavk middle of the ice and get hit pretty hard... Next time do you think, you will react the same way or thinking a little longer and maybe hesitate? Maybe stay a little more on the board and taking 1,2 for second to attack the D. so physicality help to win time. If you dont play physical what do you think will happen, they will conti u to attack him over and over again. He become to slow to follow them and will never slow you down, so you can do every thing you want and just get free entry zone all the time. Thats why brodie game declining much more faster than tanev.