Gabriel Desjardins, Puck Prospectus:
It’s hard to downplay what happens here. After you lose a faceoff in the neutral zone, you have time to set up defensively and you don’t give up a particularly large number of good scoring opportunities. However, when you lose a faceoff in your own end, opponent shots on goal go up so quickly that it’s as though you gave the other team a 10-15 second power-play. For several seconds, the rate of shots allowed is as high as it is on a 5-on-3. The prospect of this level of defensive disadvantage, particularly late in a one-goal game, must give coaches nightmares.
David Staples, Cult of Hockey:
If you think about it, when a defensive zone faceoff is lost at even strength, it's just one small lost battle for the puck, one of many such small lost battles in a game, but in this case the defence is uniquely organized. Each player has a clear responsibility so it's not such a difficult thing to recover from this particular kind of lost battle.
I probably don't even need to say it, but I think Desjardins' view of what happens here is more accurate, and is even supported by David Staples' data. Let's quote Staples again:
Last season, the Oilers let in 156 goals at even strength. I reviewed each of those goals against to determine which Oilers were at fault on each goal. In the end, I counted up 22 times where a faceoff loss directly contributed to a goal against, with 17 of those faceoff losses coming in the defensive zone, five in the offensive or neutral zones.
So out of 156 goals scored against the Oilers, 17 of them came because the Oilers lost a defensive zone faceoff, 11 per cent of the goals against.
Only 11% of the Oilers goals against at 5-on-5 came about because of a lost defensive zone faceoff. That really doesn't sound like much, until context is considered. The Oilers as a team took 763 defensive zone draws at even-strength last year, and we know they averaged 47.9% in the circle. That means that the Oilers lost approximately 398 faceoffs in their own zone at even-strength.
Further, from Desjardins' data we know that the effects of losing a draw are negligible after about 25 to 30 seconds. Let's be conservative and multipy that 398 by 30 seconds - we get 199 minutes of affected ice-time. If we convert Staples' 17 GA in 199 minutes into a ratio, we get 5.14 GAON/60 - a goals against number 150% worse than the worst player on the team last year.
Desjardins states that the shots-against rate jumps to the level of a 5-on-3 powerplay, spiking nearly to the 120 shots against per 60 level roughly five seconds after a lost draw.
That's just the even-strength effects. The effects of a lost defensive zone draw on the penalty-kill are easy to imagine as well. This also doesn't allow for the flip effect - bringing in a competent third-liner would free up Shawn Horcoff to take draws in the offensive zone - and then Edmonton could receive the benefits of winning offensive zone draws, leading to more shots for, leading to more goals.
This seems like a decision that's fairly easy to make.