Time on ice is such a great tool for breaking down fantasy NHL metrics. Goals per 60, shots per 60, Corsi per 60 ... you name it, it can be per 60. Time is the great equalizer, after all.

Except in one particular case. Time on the power play doesn't track out the same way. We can't do rate stats on power-play time and hope to glean anything because more time on the power play is both a positive and a negative variable.

Positive because with more opportunity comes more chances with an advantage. More power-play time could -- stress, could -- mean that a player is a key part of a team that gets more power plays because they draw more penalties.

But it's also negative because more power-play time could also mean an ineffective unit that can't score. Because the goal for players on the advantage is to end the power play as quickly as possible by scoring a goal. More time on the power play can be an indicator that a player is spending that time out there without producing fantasy points.

So I felt more than a little like Don Quixote as I tilted at Excel-based windmills of power-play metrics. I knew in my heart of hearts there was no enemy to slay here, but I set about the task all the same.

The problem can be captured perfectly by the following statistic: The team with the second-most power-play goals this season and the team with the least power-play goals this season have both spent the exact same amount of time on the ice per power-play opportunity. The Ottawa Senators have spent 209.05 minutes on the power play across 131 opportunities, while the Columbus Blue Jackets have spent 143.13 minutes on the advantage across 90 chances.

So if both teams spent precisely 1.60 minutes per power-play opportunity, what sense would we get from trying to use rate stats for any individual player? Any measurement of a player's statistics or fantasy points on the power play that use a per-time-unit measure needs to have the context of the team's power-play success as it relates to their time.

But I thought by getting fancy, maybe I could find something useful from the stats. After all, we have games played, power-play time on ice, power-play goals and assists, and even power-play shots for the individual player, as well as opportunities, total power-play time, team power-play goals and more for each franchise. Surely there can be some telling metric assembled from all this data?

Sadly, if you try to leave time on ice out of the equation, which was a goal because of the above discussion, you basically keep circling back around to the same basic projection you get from taking a player's fantasy points on the power-play and prorating the rest of the season based on how many opportunities a team gets. I think I found my way back to the exact same basic formula four different ways.

And guess what? It's not that telling. It mostly just shows that the best fantasy players will continue to be the best fantasy players.

But with all of this spreadsheet work done, I think I will take the opportunity to highlight a few statistics -- that go a bit deeper than simple power-play percentage -- that did pique my interest.

The traditional definition of best power play is the one with the best conversion percentage. But that doesn't factor in the efficiency of that unit. In playing with the different power-play metrics, I ended up liking this one: Power-play opportunities, divided by power-play goals (which gives you the average number of opportunities a team needed for a goal and is the direct inverse of the traditional percentage) then multiplied by the average time on ice per opportunity. The lower the number, the better the power play is in my estimation.

But even that metric has a fallacy in it. See, a power-play goal isn't the only way to end a power play. Taking a penalty does that too. The Blackhawks have taken 14 two-minute penalties while on the power play this season (per EvolvingHockey). The only way to know by how many minutes that pushed up their efficiency would be to pore over all 104 opportunities they had to see which ones were cut short by the 14 penalties and which ones were cut short because of their 22 power-play goals.

Or even take the Oilers, who easily lead the league in the shortest time on ice per power-play opportunity at 1.44 minutes. They have taken 11 penalties while on the power play this season. It's very possible that those have helped contribute to their shorter average time on the advantage than the rest of the league.

Without an elegant way to weave penalties into the equation and with the knowledge that some could have come right at the start of an advantage and some right at the end, I'm going to give out this award anecdotally.

The Ottawa Senators have the best power play in the NHL. They rank fourth in conversion rate, fourth in my inverse metric that accounts for efficiency and they have only taken five penalties while on the advantage this season, which is tied for the seventh-fewest in the league.

The Oilers have a handful more goals than the Sens (42 to 37 as of Dec. 28), but the Sens have two games in hand. It's a fantastic top unit with Alex DeBrincat, Tim Stutzle, Brady Tkachuk and Drake Batherson up front and Thomas Chabot on the point, with Claude Giroux ready to step in and Josh Norris projected to return before February. Jake Sanderson has even proven to be a quality stand-in for Chabot when need be.

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The rather laborious route taken to find some kind of predictive formula for power plays ran into the ever-present time on ice issues time and again. But the expected fantasy points calculation did point to some players -- particularly ones that have missed time or not played all their team's games -- as potential sources of increased production going forward. Player stats were clipped after Dec. 28 games from EvolvingHockey.

Alex Iafallo, W, Los Angeles Kings (rostered in 7.8% of leagues): In his 15 games, he's played 16 minutes of power-play time. Adjusting for the time he's missed injured, he would have played on a total of 18.8% of the Kings total power-play time, which is squarely second-unit territory. But he's produced two goals there and it's not as if Gabriel Vilardi has his spot on the top unit sewn up for the season. Iafallo could become a regular roster commodity if he can earn a promotion to the top unit.

Nikolaj Ehlers, W, Winnipeg Jets (65.4%): That he's not universally rostered is close to a crime. We can almost start talking about Ehlers projected return from injury in days rather than weeks. And he's a lock to return to the top power-play unit when he does return, which is where he picked up 1.7 fantasy points in only eight minutes of work in his two games at the start of the season.

Tyler Johnson, C/W, Chicago Blackhawks (3.1%): Accounting for an extended injury absence, Johnson's adjusted power-play time share is 43.9%, which is borderline first-unit range. He was on the top unit before his injury, but Taylor Raddysh has taken the spot since then. But Johnson's efficiency remains spot on, with 6.1 fantasy points in only 25.2 minutes of work this season. Should he push back into the role over Raddysh, he might be worth starting some weeks.

Alexander Holtz, W, New Jersey Devils (0.6%): He's not even a roster mainstay at this stage of the season. The Devils have recognized what they have in the young sniper and used him a few times in Ovechkin's Office during the advantage. Sure enough, he's blasted seven power-play shots and scored twice in 22.9 minutes across 14 games. His adjusted usage for time in the press box works out to 32.8% of the team's power-play time, so when he's in the lineup, the Devils are using him. But Holtz would have to crack the first unit permanently for this to mean much for fantasy this season, which feels like a reach at this point.

Jonatan Berggren, C/W, Detroit Red Wings (0.5%): A pleasant surprise to bolster the Red Wings middle six, Berggen is getting some modest power-play work, too. Adjusting for missed time, he's played 30.9% of the team's power-play time when active this season and has 10.3 fantasy points in 36 minutes on the advantage. Unfortunately, there is probably less opportunity coming Berggren's way as Jakub Vrana started a conditioning stint in the AHL and Tyler Bertuzzi is about two weeks out from his projected return.

Bowen Byram, D, Colorado Avalanche (20.8%): This is the injury that has dragged on seemingly more than most others this season. It's felt like Byram has been day-to-day almost since his last game on Nov. 4. In the 10 games he did play this season, he played as the second-unit quarterback on the advantage and earned 1.8 fantasy points in only 11.9 minutes of work. Keep in mind, whenever Byram is back, that this second unit for the Avs will get much better with trickle-down health. Nathan MacKinnon and Gabriel Landeskog could both be in the lineup two weeks from now (MacKinnon sooner than expected).

Dylan Guenther, W, Arizona Coyotes (0.4%): When he comes back to the desert after his loan to the World Junior Championships, Guenther has a chance to do more damage on the advantage. He has three power-play goals fueling 11.1 fantasy points in 45.7 minutes. His share is clearly second unit, but the Coyotes have a decent power play from both units, so it's not a bad place to be.