Someone once asked J. Paul Getty how much money was enough, he replied, "Just a little more."
In sports, the fields are 100 yards long and very wide. I have been using a Sigma 300 2.8 at night as my long lens for years. In daylight I use Tamron 150-600 5.6, which works just great. However, in night sports, the Tamron lens is not a viable option for me. I need "just a little bit longer reach" at night sports. So, I bit the bullet so hard, I bit it in half, and got a 400 2.8 VR, to ease my pain. It will go into service on Friday night. I enjoy shooting tight and hopefully this monster will help me get better images. It has a VR setting "sports" so that justifies the purchase right there. 8-)