roots, but I failed to mention that the deep tine is a big part of that. From the pictures below, root depth and hole depth are almost equal.
Aside from great rooting, we get better air/ water exchange through the soil profile and we also break up the small pan layer we have. A pan layer is formed typically around 3.5" deep where normal greens aerators typically go down to. When inserting a soil probe, you'll feel it get much firmer to press in at this layer and water will also have a hard time getting through that layer.