2007-11-28

Puck Luck

They're off to a good start. Still, Habsland has this nagging feeling. The ominous shadow of last season hangs over this team. They were off to an even better start in 2006 when the wheels fell off. We can blame 2006-07 Maple Leafs MVP c difficile all we want, but deep down we all know they were doing it with smoke and mirrors.

The $64,000 question is, Will the same thing happen this year? Let's pop the hood and look for some warning signs through the first 24 games.

1. Even Strength

All stats in this post are from behindthenet.



I'm only including the 4-on-4 info for the sake of completeness. It's irrelevant compared to 5-on-5.

First off, the +32/-43 in 5-on-5 play looks like trouble. It's eerily reminiscent of last year. Good teams don't get outscored 4:3 at even strength. The shot differential is negative, but it's nowhere near this 4:3 ratio. They're only being outshot by 1.3 shots per game, 5-on-5.

If you look a little closer, you'll find the Save percentages are the difference. The league average EV Sv% is .916 (calculated by adding up each team's Sv% and dividing by 30). As expected, Huet and Price are above average at .924. Montreal shooters have been making opposing goalies look like Tretiak. Collectively, they have had a .940 Sv% - the Habs have been shooting 6% at ES. Only the Rangers have been worse, at 5.4%. I can accept that Montreal shooters are below average, but this looks suspiciously like a run of bad puck luck.

What if we plug in some numbers to account for the bad luck? If opposing teams merely had the same kind of goaltending Huet/Price provided at ES (a solid .924 Sv%), Montreal still would have scored an additional 8 goals. I think it's fair to keep the Habs' .924 Sv% as is - goaltending is a team strength. Here's the revised table:




If Montreal could shoot a below-average 7.6% rather than an abysmal 6%, they would only be outscored 40:43 at ES. If they could shoot at a league-average 8.4%, they would be outscoring opposition 45-43. But let's not get carried away. Shooting 7.6% is a reasonable goal for a team comprised of four 4th lines.

Puck luck at even strength: Unlucky by 8 goals (-8)


2. Power Play

It's a different story on the PP - shooting percentages are abnormally high.




League average Sv% are .870 for 5-on-4 and .750 for 5-on-3. As unlucky as the Habs have been at ES, they've been extremely lucky on the PP. We can be pretty sure that the Habs PP is good, this being it's second successful year in a row, so we'll grant them a 5-on-4 Opposition Sv% of .850. That's still a lot better than average, but you have to consider that had they not scored on some of those 'lucky' shots, the PP would have continued and they would have had more shots.



Puck luck on the PP: Lucky by 4 goals (+4)


3. Penalty Kill



Things look normal for the 4-on-5 penalty kill. League average Sv% is .870 - Price/Huet performing at .882 is reasonable. The 3-on-5 Sv% is way out of whack. They're giving up fewer goals per minute when down two men than when they're down one. Those numbers will change by the end of the season. A .760 Sv% is more reasonable for 3-on-5 situations. With some rounding, that means 4GA rather than 1.



Puck luck on the PK: +3 goals, all 5-on-3

3a. SHGs

The other piece of puck luck on special teams is the 4 shorties scored and none allowed. Last season, the Habs scores 15 and allowed 5. There is probably some repeatability there, but not the 3:1 ratio. I'll use a completely arbitrary and unjustifiable 4:3 ratio as reasonable. This means the Habs are up another 3 goals here due to luck.

Puck luck with SHGs: +3 goals


4. Penalties taken/drawn

On average, Montreal is on the PP for 7.6 minutes per game and spending only 6.8 minutes on the PK per game. The success of the PP means that the difference between penalties drawn/taken is even greater. This is a huge improvement over last season, and it's a bit of a wild card. I'm not optimistic that they'll be able to sustain this, but then again I'm wrong an awful lot.

If the Habs conformed to the league average, they would have been on both the PP and PK for an equal 7.3 minutes per game. This would have resulted in a 2 goal swing downward - instead of scoring 4 more PPGs than their opposition, it would be down to a +2. However, I'm going to call this one a wash because they just might be able to continue drawing more penalties than they commit.

Puck luck on penalty differential: 0


5. Empty net goals

They've scored 3 and allowed 4.

Puck luck on ENGs: -1 goal


6. Goalposts

As of Nov. 23, the publication date of this post at IOF, opponents hit seven more posts than did the Habs.

I don't know what to make of this. There is some debate regarding the accuracy of the stats. No one calls shots that go off a post and into the net 'lucky' for the shooter, but shots that hit the post and stay out are somehow 'lucky' for the goalie. There must be some number of goalposts hit that would have been saves if the shot had been aimed an inch or two closer to the centre of the net. Intuitively, something tells me the luck value of a goalpost is not more than half a goal. I'll call the -7 goalpost differential equivalent to 3 goals worth of luck. I'll allocate two of those to 5-on-5 and one to 4-on-5.

Posts: +3 goals.


Total: Habs have been lucky by 4 goals. Instead of a +7 differential (69GF, 62GA) in these situations, we should have expected only +3 (73GF, 70GA). They may not be quite as good as their record indicates, but they're not a sub-.500 team either. As long as no major injuries strike, everyone gets their flu shot and there are no lengthy skids of bad luck, they should stay above .500 and make the playoffs.



Update: It looks like I might have double counted a shorthanded empty net goal. It doesn't change the conclusion much - the good luck on the PP and 3-on-5 PK has been countered by rotten luck scoring at 5-on-5. The team should be able to maintain a slight positive goal differential.

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2007-11-21

Ryder Criticism. Alan Ryder, that is.

I read all of Alan Ryder's columns at the Globe & Mail. I'm a fan of his and it's great that he has a mainstream forum for his number crunching. Ryder's latest piece is on one of his hobby horses - respecting the shootout.

His conclusion is that there is little correlation between a goalie's hockey performance and shootout performance, therefore coaches and GMs need to spend more time thinking about the shootout. Especially those crotchety old-schoolers North of the border. To be honest, I find his dismissive tone of 'traditional hockey values' getting in the way of smart decisions a little insulting.

According to Ryder's table, there have been 337 shootout points awarded. Over the same time span, there have been 3373 non-shootout points awarded. That 3373 includes wins and OT/SO losses. So it's fair to say that the importance of the shootout is one ninth of the importance of regulation/OT NHL hockey.

For the most part, NHL coaches aren't morons. Say a coach has to decide between two players available to dress for a game. The two have identical regulation/OT performance but one happens to be a shootout ace. The decision is obvious in this case. The difficulty arises when there is a trade-off.

Let's compare Player A and Player B. Player A is fantastic in shootouts - he contributes 0.5 points more than Player B for every shootout. Unfortunately, he's not quite as good at regulation/OT hockey and contributes team 0.1 points per OT/regulation game less than Player B. Player A's net contribution:

0.5ppg*(1/10) - 0.1ppg*(9/10) = -0.04ppg

So Player A contributes 0.04 fewer points per than player B.

Similarly, if player C costs you 0.5 points per shootout but gains you an extra 0.1 points per regulation/OT, he's worth 0.04 points per game more than player B. Because of the rarity of the shootout, regulation/OT performance is much more valuable than shootout performance.

To sum up: Although 1/10th of all available points is a significant fraction, 9/10ths of all available points is nine times more significant. If you're facing a trade-off, you need to gain 9x more shootout value than you lose in regulation/OT value.

Next, let's look at Ryder's table of team shootout performance and compare it to regulation/OT performance:


Click the table for a clearer image. The SO record columns are copied from Ryder's table. I got the Non-SO record numbers from NHL.com.

The correlation between SO% and Non-SO% is -0.15. Good shootout teams are slightly less likely to be good 65-minute teams and vice versa.

The negative correlation is small but significant and completely unsurprising. It suggests the trade-off between shootout performance and 65-minute performance is real. Kiprusoff sucks in shootouts, but wins a lot of games for the Flames. Jussi Jokinen isn't that special in the first 65 minutes (recent 4-goal games notwithstanding), but is crackerjack in the shootout. Ryder's perspective that there is a lack of 'market competition' is explained by some teams having regular players that happen to be great shootout performers (i.e. Dallas), and some teams having great regular players who happen to be lousy shootout performers (i.e. Calgary).

To be fair, the main thrust of Ryder's article is that the backup goalie should come in as the closer for shootouts if he is the better shootout performer. It's a good point. The reason it doesn't happen is probably because coaches prefer not to put a 'cold' goalie in that situation, either due to injury concerns (seems goalies do the splits a lot in shootouts) or concerns about the performance of a 'cold' player. I'd like to see evidence that a player can be put in this situation regularly and perform at his usual 'warmed up' level without a greater risk of injury before I'd endorse the idea. Raycroft looks like the perfect guinea pig for the experiment.

Update: Ryder responded to my comment on his article thusly:

"You are absolutely correct that the shootout is 'only' about 10% of the game. But 'only' 3-4 players per team affect that 10%. And, of course, the goaltender is always one of those players. In the case of forwards the leading shootout contributions of all time have come largely from guys who don't perform at the same level in skating time. They are, in effect, shootout specialists. The shootout tests finesse. But the Leafs trot out their power forwards. The story with goaltending is more complex. You would not choose a single goaltender based on a stand-out shootout record. But, just maybe, you might choose a backup based on that metric AND use him as your closer."

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