Tuesday, September 22, 2009

Season Preview: Pittsburgh Penguins

In terms of regular season results, the 2008-09 Penguins do not compare favorably to the majority of recent Stanley Cup champions. In fact, outside of the 2005-06 Hurricanes, the only teams that had similarly mediocre numbers were, perhaps fittingly, the Lemieux Penguins of the early 90s.

For reasons articulated in this post, the Lemieux Penguins were better than their regular season results would suggest. I would argue that the same was also true of last year’s team.

The Penguins 2008-09 season can essentially be divided into two distinct parts: that which preceded the coaching change, and that which followed it. As has been discussed on this blog before, the team’s performance improved substantially following the coaching change. While it would be inaccurate to award all of the credit for the turnaround to Bylsma – as the acquisitions of Guerin and Kunitz, as well as the return of Gonchar from injury, surely had an impact as well – it’s nevertheless apparent that the team markedly improved under his tenure.

It’s difficult to overstate how much better the Pens were after the coaching change. The shot for and against numbers are especially telling. For example, consider the difference in Corsi differential per game between the Penguins under Bylsma (2.8) and Therrien (-3.39). That’s a considerable difference. To put those numbers in context, that’s equivalent to the difference between the 4th best team (the Capitals, at 3.05 per game) and the 2nd worst team (Atlanta, at -3.21 per game) last season. In other words, the Penguins basically went from being one of the worst teams in the league in terms of territorial play at EV to one of the best.

The difference is even more remarkable if one considers that the intra-season split-half reliability for EV shot differential at the team level is huge. For example, among NHL teams last season, the correlation between EV shot differential in the first half of the season and EV shot differential in the second half season was 0.82. Suffice it to say that few teams experience large swings in shot differential from one part of the season to another. Fewer still experience swings of the magnitude described above.

In terms of forecasting, few teams had underlying numbers as good or better than the Penguins did down the stretch and, given that their current roster is similar in composition to last year’s team, I think it's sensible to assume that the same will be true this season. The results may not be present to the same degree -- the Penguins EV shooting percentage with the score tied was almost twice as good as that of their opponents during the stretch in question, which is simply not viable in the long run. Nonetheless, they’re probably the best team in the East at this point in time and I suspect that that they'll finish as a top four seed in the conference. While I don’t necessarily expect them to win the cup again – as they’re not obviously better than any of the other potential contenders, a repeat is certainly conceivable.

Sunday, September 20, 2009

Season Preview: Colorado Avalanche

Colorado was a terrible team last season in terms of goal differential and their placement in the standings. However, to what extent they were bad, and to what extent they were unlucky, remains unclear.

At first glance, the latter appears to be true. The Avalanche were absolutely screwed by the percentages in 08-09. At even strength, they ranked 27th in shooting percentage and 26th in save percentage. On special teams, they ranked 25th in shooting percentage and 24th in save percentage. Overall, they ranked 29th in shooting percentage and 28th in save percentage. That’s undeniably rough.

However, the above data doesn’t quite tell the entire story. For one, it’s been demonstrated that shot ratio and shot differential at EV varies according to goal state. Whereas playing from behind tends to increase shot ratio, playing with the lead tends to decrease it. Therefore, shot differential per se may not be indicative of the balance of play for a team that plays a disproportionate amount of time with the lead or while trailing in any given season.

Colorado qualifies as one such team. No team played from behind more than the Avalanche did in 08-09. Not surprisingly, this is reflected in the team’s underlying numbers. Whereas the Avalanche ranked 16th in the league in terms of overall EV shot differential, they were 24th in terms of EV shot differential when the score was tied.

Secondly, while the Avalanche may have been respectable in terms of shot differential itself, they fared quite poorly in terms of Fenwick and Corsi. For reasons that remain unknown, the Avalanche tended to surrender many more missed and blocked shots than their opponents last season. In other words, the Avalanche had many more shots directed at their own goal than they directed at the opposition’s net.

Admittedly, I’m not quite sure what to make of the fact that the Avalanche fared so much worse in terms of Fenwick and Corsi relative to their shot differential. No other team in the league exhibited such an unusual discrepancy. On the one hand, it may suggest that Colorado tended to spend much more time in their end of the rink than in the other team’s end at EV. Such is the mark of a poor even strength team. If the Avalanche were in fact territorially dominated at EV last season, their results may have less to with poor luck and more to do with poor play.

Interestingly, the 07-08 Avalanche were characterized by the exact same profile. Like the 07-08 team, their EV shot differential was much better than their Fenwick and Corsi. Unlike the 08-09 team, however, the 07-08 Avalanche performed quite well at even strength, outscoring the opposition 160 to 143. Unless the 07-08 Avalanche were simply lucky – which I think is unlikely, it’s possible that shot differential is more indicative of Colorado’s EV ability than are Fenwick or Corsi.

Additionally, even if the Avalanche are evaluated on the basis of Fenwick and Corsi, and even if one controls for the fact that the Avalanche tended to disproportionately play from behind last season, it remains apparent that they were an unlucky team. To illustrate this, I’ve prepared a chart below, based on data kindly supplied to me by frequent poster Sunny Mehta several months ago, that shows how each team performed last season in terms of Corsi when the score was tied at EV.

In this chart, I've included two columns that show each team’s shooting and save percentage in terms of shots directed at the net with the score tied. Thus, shooting percentage is calculated by taking the number of goals that a team scored at EV with the score tied, and dividing it by the number of total shots directed at the other team's net. Save percentage is calculated in the exact same fashion, except with goals against and shots against. As depicted in the chart, the Avalanche ranked 22nd in shooting percentage and 24th in save percentage. The point is this: the Avalanche were an unlucky team any way you look at it, regardless of the particular approach or method of analysis.

All things considered, the Avalanche were likely a below average team that also happened to be subjected to an inordinate amount of bad luck. I suspect that they’ll be less awful this year just on account of the fact that they couldn’t possibly have a worse year with the percentages than they did last season. For the exact same reason, they’ll likely do better than most people expect them to. That said, the team lost one of its best forwards in Ryan Smyth in the offseason and had its second line centre retire. They’re worse on paper than they were at the beginning of last season and I’d be surprised if they made the playoffs.

Season Preview: Minnesota Wild

I've been preparing some previews for the upcoming NHL season over the past several days. While I don't anticipate that I'll cover every team, or perhaps even most of them, I figured that I'd post what I've generated thus far between now and the start of the season.

The Wild had an overall goal differential of +15 last season and probably deserved to make the playoffs on that basis – the Blues, the Jackets and the Ducks were all worse than Minnesota in terms of goal differential.

The Wild’s success last season was based almost entirely around their penalty kill. Not only did they limit the opposition to very few powerplay opportunities, but they allowed very few goals while shorthanded – in fact, they led the league in both categories.

As displayed in the above chart, the Wild were merely average last season in terms of preventing shots on the penalty kill. Their secret to goal prevention was their excellent – nay, absolutely ridiculous – PK save percentage of 0.92. That’s over 10% better than Toronto, and better than about how half of the league's teams fared in terms of EV save percentage.

While it’s true that PK save percentage is characterized by a high degree of randomness, the Wild have consistently been among the league leaders in PK save percentage in every post-lockout season. Their PK save percentage was 0.894 in 0708, 0.898 in 0607, and 0.886 in 0506. In other words, they're well above the league average during that time period and, interestingly, much better than what one would predict on the basis of their team EV save percentage (as discussed by the Contrarian Goaltender in a recent post of his).

I’m not sure to what extent this is reflective of the ability of Minnesota’s goaltenders and to what extent it reflects team factors, although both are likely operative to some degree. If team factors are involved, it’ll be interesting to see what effect the departure of Lemaire will have.

In any event, a PK save percentage of 0.92 is clearly unsustainable in the long run and it’s reasonable to anticipate some regression. I suspect that they’ll end up a near the 0.89 mark next year – that is, at or around their post-lockout average.

Any deficits that the Wild experience on special teams may be offset, at least partially, by an improvement at even strength. The Wild were a below average team at even strength last season in terms of their results and underlying numbers. However, they were without Gaborik, who was arguably their best forward, for almost the entire season. Had Gaborik been healty, I suspect that the Wild would have done somewhat better at even strength, particularly in terms of goal scoring.

The Wild have effectively replaced Gaborik with Martin Havlat. Quite frankly, I love the Havlat acquisition and I think that the Wild will be an improved even strength team because of him. While he’s not quite the goalscorer that Gaborik is, he’s probably the better all-around player. The Havlat – Bolland – Ladd line played tough minutes at even strength for the Hawks last year and posted some impressive results in doing so. I tend to attribute a great deal of that to Havlat, who, unlike his linemates, has a history in the league as an even strength outscorer.

In looking through the standings predictions that have been issued thus far, few have Minnesota as making the postseason and many appear to be discounting their playoff chances altogether. I think that’s a mistake. I expect that the Wild will at least compete for a playoff spot. There are about seven teams in the West that are all pretty similar to one another in terms of ability and I suspect that only three or four of those teams will make the postseason. As I happen to include the Wild in that group, I think that their playoff chances are somewhere around 50%. As always, luck and injuries are bound to determine a whole lot.

EDIT: For whatever reason, I thought Laviolette was now coaching the Wild. As it appears that they hired Todd Richards instead, the sentence referring to Laviolette and the Hurricanes has been removed.