I say it is a combination of 3 roughly equal major factors: (1) Berube installing a defensive system, fixing Yeo's chaotic non-systemic team defence; (2) Binnington's solid play in goal, which instills confidence in his teammates' play, replacing Allen's erratic play, which forced his teammates to play in fear "not to lose"; and (3), the new teammates believing in Berube's system, trying hard to make it work, and finally gelling together. O'Reilly's excelling, and Bouwmeester's returning to health are part of that, but play less of a role than the 3 factors listed above.