With James van Riemsdyk out long-term with a broken foot, Josh Leivo has been called up from the Toronto Marlies to provide a bit of a scoring punch to the Maple Leafs. He's having a career year, with 30 points in 35 games so far, a big improvement over last year's output (32 points in 51 games). The question on my mind, and perhaps yours as well, is whether Leivo's improvement is real or whether he's just getting lucky.

I have been a critic of Leivo in recent years. In our Top 25 Under 25 this past summer, PPP collectively ranked Josh at #15, but I had him way down at 25. Even though his scoring's gone up dramatically this year, I've remained unconvinced that he has a good shot at becoming an NHL regular. The thing that jumped out at me was the huge jump in his assists this season. My guess was that Leivo was getting a big boost from playing with William Nylander, and that was making his statistics look misleadingly good.

It's well and good to have a theory, but does the evidence actually back up my guess?

The Nylander Effect

There were a few things I wanted to look into, but the first one was pretty straight-forward: how much of Josh Leivo's offensive production this year has involved William Nylander? If Leivo was picking up a lot of assists on Nylander goals (especially secondary assists) or if Nylander had the primary assist on most of Leivo's goals, we might be able to dismiss Leivo's output as the product of his supremely talented centre.

It turns out that isn't the case. William Nylander has a point on 13 of Leivo's 30 points this season, fewer than half. That number falls even further if you take out Nylander's secondary assists. [Secondary assists are mostly random and shouldn't be read as skill.] Nylander has a goal or the primary assist on just 9 of Leivo's points this season. That's a much smaller proportion than I would have guessed.

It's impossible to account for other things Nylander might be doing that could potentially be affecting Leivo's scoring (like drawing away defenders, making clean zone entries, etc.), but based on the evidence I can find, I don't think it's fair to credit Nylander for Leivo's improvement.

Where is the Improvement Coming From?

If Leivo isn't just the beneficiary of being put on Nylander's wing, can we find some other explanation for why his scoring has increased so much?

Some of the possible explanations are things I can't check with the limited amount of data the AHL releases. For example, maybe his ice time is way up, or maybe he's having a lucky run of high on-ice S%. But we can't look at the things we can't look at, so let's look at the things we can.

Here's Leivo's per-game assist rate for each of his three AHL seasons.

Season A/GP 2013-14 0.32 2014-15 0.41 2015-16 0.54

The uptick this year is bigger than the one last year (.13 vs .09), but there's a pretty clear progression. We see the same thing with his shots per game (a better indicator than goals-per-game because shooting percentage fluctuates so much year-to-year):

Season S/GP 2013-14 2.37 2014-15 2.55 2015-16 2.71

Leivo's shots-per-game aren't as high as Nylander's (3.18), but they're comparable to what a couple of good NHLers did in the AHL at the same age. Nazem Kadri had 2.70 shots per game in the AHL in his 22 year old season, and Gustav Nyquist had 2.71 at that age. (Disclosure: I have no idea what's normal for a player of that age. I just looked up the first two recent-ish players I could think of who played a bunch of AHL minutes.)

Assists Again

I mentioned earlier that secondary assists are mostly random, so we shouldn't put much stock in them. It follows, then, that we should put more stock in primary assists. And that's an area where Leivo looks quite good. He currently leads the Marlies with 16 primary assists (slightly more per-game than Nylander), and his propensity for primary assists is not a new thing this season:

Season 1A 2A 2013-14 12 7 2014-15 16 5 2015-16 16 3

If anything, Leivo should probably have more assists; a 4:1 ratio of primary-to-secondary assists is unusually high, and could be an indication that he's getting some bad luck as far as picking up secondary assists goes.

Another question you might ask is whether Leivo is picking up all these points on the powerplay, but that's not the case. He's 2nd in the AHL in primary points at even strength right now.

So About That Hypothesis

I started with the belief that Leivo was just lucky to have been paired up with William Nylander this season, and that expectations for him should be tempered accordingly. But every piece of evidence that I look at is contrary to what I expected. Nylander has factored in on a fairly small number of Leivo's points. There's a pretty clear progression to Leivo's output year-over-year, and his high volume of primary points suggests that there's some real skill there.

I'm not ready to vault Leivo up into the top echelon of Leafs prospects, but I have to admit I under-estimated his skill level. He looks like a player with a real shot to have a decent NHL career.