OTTAWA — When Mike Babcock took the Leafs’ bench for the first time as their head coach on Oct. 7, 2015, he might as well have had two fourth lines.



His quote-unquote third line, featured Daniel Winnik, Nick Spaling and P.A. Parenteau. His fourth line slotted Peter Holland between Leo Komarov and Mark Arcobello.



The Leafs lost that game 3-1, and in the bulk of the 245 regular season games that have followed, Babcock hasn’t been satisfied with the sum of the parts that have made up his fourth line.



Today, none of the six players who made up his bottom-six three years ago remain. Winnik, Spaling and Parenteau were always meant to be trade bait. Babcock wasn’t especially fond of Holland and Arcobello from Day 1. And Komarov, the lone player he grew to like, played higher in the lineup than the fourth line for the bulk of those three seasons.



A year after Babcock’s debut, he opened his second season as Leafs head coach with...