Jyelly pretty much nails it. The only things I would add are that the only players who "relax" in straight cbmm playlists are the top 10%. Everyone else sweats twice as hard. I'd also point out to those who don't know, D1 had sbmm from Day 1, it just was weighted much lower in year one and was raised in TTK because of player complaints about hugely mismatched games.