Points came so easily for the Mavericks in their series against the Clippers until suddenly they didn’t, a torrent of offense reduced to a trickle. The freewheeling drives of Luka Doncic turned arduous over the last two games; the first-round series may have swung with the neck strain Doncic suffered Friday night during Game 3, as since we’ve seen the joy of his do-it-all game come out only through gritted teeth. Without the fullest effect of his creativity and vision, Dallas pinned its scoring hopes to a streaky supporting cast in the midst of a jarring and dramatic correction. In the first three games of the series, the Mavericks stayed one step ahead of every Clipper adjustment by moving the ball and hitting 50.5 percent of their shots from beyond the arc. In Game 4, they made just 16.7 percent, erasing any hope of a comeback in what would be a 106-81 defeat, knotting the series at two games apiece.