After a couple weeks of the Blackhawks' effort meter flickering up and down, it crashed to near zero in their penultimate game Monday.

Mental and emotional engagement were visibly lacking in a 5-1 loss to the Sabres, who are heading to the playoffs for the first time in 15 years.

Nothing summed up the Hawks’ futility more than a line change after a penalty kill that they bungled to an almost comical degree, allowing Tage Thompson to bury the Sabres’ fourth goal.

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Later, the Hawks’ backcheck after a turnover by Wyatt Kaiser in the offensive zone was arguably even lazier than the line change.

An announced crowd of 17,056 — which appeared several thousand short of that figure — missed no opportunities in the third period to boo the Hawks, to the point that in-arena host Jon Hansen joked about it during a commercial-break gimmick.