Feb 182011
 

First off, it should be a sad day in Leaf land as we all say good bye to Tomas Kaberle.  It seems many people are unaware of just how good Kaberle was and still is.  Here are some facts about Tomas Kaberle:

  1. Since Kaberle entered the NHL in 2008-09 the only defenseman with more assists than Kaberle is Niklas Lidstrom and only Lidstrom, Gonchar and Pronger have more points.
  2. Since the lockout only Lidstrom has more assists among defensemen and only Lidstrom and Rafalski have more points.
  3. Among all skaters, not just defensemen, Kaberle ranks 20th in assists since the lockout and has more assists than Vincent Lecavalier and Eric Staal.
  4. His point production has not tailed off significantly the past several seasons despite many people seemingly believing otherwise.  He had 49 points last season and is on pace for about 52 this season.
  5. Only 2 defensemen (Keith, Enstrom) have more combined assists this season and last and only 8 defensemen (Green, Keith, Boyle, Lidstrom, Enstrom, Visnovsky, Doughty and Yandle).

That is pretty good if you ask me and while he had his flaws he truly was an elite puck moving and passing defenseman.  He’ll be missed in Toronto.

Now, it is time to take a look at the Leafs future.  What Burke has done the past couple years has actually been pretty extraordinary and for all those who have begged for the Leafs to go with the build through the draft method of team building here is some of the assets currently in the Maple Leaf organization.

  • 2011 Boston 1st round pick
  • 2011 Philadelphia 1st round pick
  • Nazem Kadri – 7th overall 2009
  • Luke Schenn – 5th overall 2008
  • Joe Colborne – 16th overall, 2008
  • Jake Gardiner – 17th overall, 2008
  • Phil Kessel – 5th overall, 2006
  • Dion Phaneuf – 9th overall 2003
  • Joffrey Lupul – 7th overall 2002
  • Mike Komisarek – 7th overall, 2001
  • Fredrik Sjostrom – 11th overall 2001
  • Colby Armstrong – 21st overall, 2001

Now we don’t know what Kadri, Colborne, Gardiner and the two 2011 draft picks will turn out to be, but that is what rebuilding through the draft is all about (and isn’t that what Leaf fans have been demanding).  So while it may not be the traditional build through the draft, what Burke has done to the depth of young talent on these Leafs has been amazing, even if we haven’t seen the results on the ice yet.  On top of that, the Leafs should have about $25M in cap space available for next season (though MacArthur, Bozak, Schenn and Gunnarsson need to be re-signed). Fear not Leaf fans, I believe good times are ahead, and not too far away.

Feb 102011
 

I have seen and heard a lot of comments on the Beauchemin for Lupul and prospect Gardiner trade with respect to Lupul’s value and most of them suggest Lupul was the cost Burke had to pay to have Gardiner included in the trade and that Lupul doesn’t have a lot of value and won’t likely score 25 goals.

From Bitter Leaf Fan Page:

Lupul may be a top six player on the Leafs but this is more a testament of just how thin the Leafs top six is, than it is an indication of Lupul’s so-called talent;

I doubt Lupul pushes the 25 goal mark as many have suggested. He’s only crested that mark twice in 6.5 seasons and it’s rare for an oft-injured 28 year old to suddenly find a scoring touch;

In general, that seems to be the sentiment though there are exceptions.  But honestly, I think everyone is down playing Lupul’s potential to perform.  If you just quickly take a look at his stats you’ll see this:

  • 2005-06:  28g, 53pts, 81 games
  • 2006-07:  16g, 28pts, 81 games
  • 2007-08:  20g, 46pts, 56 games
  • 2007-09:  25g, 50pts, 79 games
  • 2009-10:  10g, 14pts, 23 games
  • 2010-11:  5g, 13pts, 26 games

So, in 6 years he has only scored 25 goals twice and only scored 20 goals half the time, but that is in large part due to his injuries.  If we prorate his goals scored to 82 games each season his goal totals would be 28, 16, 29, 26, 35, 16.  Looking at those totals and things seem a little more impressive.  He’d have been a 4 time 25 goal guy in the past six seasons.  The two seasons he didn’t reach 25 goal pace was an awful season in Edmonton on an awful team and this current season when he has been recovering from a serious back injury and has seen his ice time fall and has played more time with lesser talented players.  Over his entire career he has scored 117g in 421 games which works out to 23 goals over 82 games.  In the playoffs he has scored 14g in 39 games which equates to 29 goals over 82 games.  Based on this there is no reason not to expect Lupul to be a 25 goal guy, maybe even more, if he is healthy.  Over the past 3 seasons there has been an average of 63 twenty five goal scorers (or just over 2 per team) and 110 twenty goal scorers (or under 4 per team) so I am perfectly happy to see the Leafs add another one to their lineup which already included 3 guys (Kessel, Grabovski, Kulemin) who should reach 25 this season and two more who should/could reach 20 (MacArthur, Versteeg).

Now I’ll grant the naysayers that Lupul’s health is a question mark and whether he can return to pre-back surgery and subsequent infection form is a question mark, but it is certainly a question mark that is smaller (probably much smaller) than any question marks that would come with a draft pick or a 20 year old prospect who has never played an NHL game (see Caputi, Luca).  As for Lupul’s salary, who cares.  Yes, it is probably $1.5M on the high side, but the Leafs have ample salary cap space this season and going forward and if they need more have the financial ability to bury contracts in the AHL (see Finger, Jeff).  I don’t see it as an issue.

All in all, I love this trade for the Leafs.  They traded a good, but not irreplaceable defenseman for a potential 25 goal winger and a good defense prospect.  They haven’t really solved their #1 center hole yet, but they have really filled in the parts around that hole nicely.  If they could just plug in Brad Richard’s I’d be more than happy with next seasons group of forwards.

Kessel-Richards-Lupul
MacArthur-Grabovski-Kulemin
Versteeg-Kadri-Armstrong
Brown-Brent-Orr
Jan 302011
 

Yesterday there was a post on the Behind the Net Blog which discussed the Washington Capital’s 2009-10 even strength shooting percentage of 11.0% and the conclusion was that it must be mostly luck which resulted in a shooting percentage that high.  But was it?  It was noted in the article that in 2007-08 the Capitals shot at 8.1%, in 2008-09 they shot at 8.2% and this season they are shooting at 8.2% again.  So clearly 2009-10 appears to be an anomaly, but was it a luck driven anomaly or something else?

Most people in the hockey analysis world have been using a simple binomial distribution to simulate luck so I’ll do that here too.  The thing is, if the Washington Capitals were really a 8.2% shooting team last year, the chances of them shooting 11.0% or better on 2045 shots is a mere 0.0042%.  That kind of luck we should expect once every 8000 NHL seasons.  In short, we can be pretty confident that the Capitals 11.0% shooting percentage wasn’t all luck driven.

So the next question is, how much of it is luck, and how much can we attribute to other factors?  Well, let’s assume that their good luck was significant to the point where there would only be a 5% chance they could have experienced even more luck.  We can do this by constructing a binomial distribution using centered on a shooting percentage where the chance of producing a shooting percentage of >11.0% is 5%.  The result is shown in the following chart:

The far left vertical line is the number of goals that Washington would produce if they had an 8.2% shooting percentage and the far right line is their actual shooting percentage.  The center vertical line is the theoretical shooting percentage we would need to meet the 5% luck conditions outlined above.  Under this scenario one could suggest of the extra 57 goals that Washington scored above what they would get if they shot at 8.2%, 22 of those goals can be attributed to luck and 35 can be attributed to skill.

But what if we assumed the Capitals were extremely lucky and there was only 1% chance of having greater luck.  Under that scenario their true talent level would be 9.49% shooting percentage and 26 goals would be due to skill and 31 would be due to luck.

Regardless of how you want to look at it, a significant portion of the Capitals elevated shooting percentage was likely due to non-luck factors, be they actual talent, playing style, score effects, etc.

Jan 092011
 

The Los Angeles Kings have signed Jack Johnson to a 7 year contract extension which will pay him $3.5 million the first 3 seasons and $5 million the final four seasons with a cap hit that works out to a cap hit of $4.36M per season.  So the question is, is it a good deal for the Kings?  I am not sure it is.

First, let me start off by saying that I really don’t watch the Kings that much so I haven’t seen Jack Johnson play all that much.  My comments here are based purely on a statistical analysis.  For some of you that makes these opinions objective, for others it probably means you think I am out to lunch, how can you fairly evaluate someone without having watched him a lot.  So be it.

So, lets start off with the good.  Over the past couple of seasons he has significantly improved his offensive output, especially on the PP.  In 2007-08 he had 3g, 11pts in 74 games.  In 2008-09 he had 6g, 11pts in just 41 games.  Last season was a bit of a breakout year for him as he posted 8g, 36pts in 80 games and this season he has taken that up another level with 4g, 31pts in just 41 games.  That said, the majority of his point production increase this season has been on the power play where he has 3g and 21 points or 68% of his points vs 36% one year ago.  Of course, his PP ice time has risen from 2:48 a game to 4:02 a game so that was a factor.  His PP performance so far seems to be coming at the expense of Drew Doughty who has seen his PP points drop significantly this season from last.    He had 23 even strength points last season and is on pace for 20 this season so even strength there is no real improvement.

Now for the bad, or should I say ugly.  It can be shown that statistically he has been and still is one of the worst defensive defensemen in the NHL.  Of the 110 NHL defensemen who have had 200+ minutes in 5v5 game tied situations, Johnson ranks 109th in my HARD+ rating system with a 0.588 score (a 1.00 score would be an average defenseman) which evaluates a players defensive performance while taking into consideration the quality of both his teammates and the opposition he plays against.  This isn’t anything new.  Of the 92 defensemen who played 400+ 5v5 game tied minutes last season Jack Johnson finished dead last in my HARD+ rating.  If you are one of those people who prefer to use fenwick/corsi, Jack Johnson finished 86th of 92 in my FenHARD+ rating last season.

If you don’t fully understand my HARD+ rating systems that’s OK, you can take a look here to see all Kings defensemen sorted by FenF% (Fenwick For / (Fenwick For + Fenwick Against) and you will see that last season he was dead last among Kings defensemen with 50+ minutes 5v5 game tied.  To to be fair, he is a bit better so far this season in FenF% but that isn’t the case in GF% (goals for / (goals for + goals against)).  It seems the coaches are questioning his defensive responsibility as well as his short handed ice time has been cut from 1:35 a game last year to 1:07 a game this year.

No matter how you look at the numbers, Jack Johnson has probably been  somewhere between bad and dreadful defensively thus far in his career and while he looks to be developing into a good, or maybe very good, offensive defenseman, particularly on the PP, one has to wonder if making a 7 year big $$ commitment to him was a wise decision.  It probably isn’t unusual for defensemen to improve their defensive skills as they age but Johnson has a long way to go to even become an average defensive defenseman.  It was a risky signing in my opinion that the Kings may regret down the road.  It’s a lot to pay for a PP specialist, especially when you already have Doughty, a much better player in all aspects of the game including probably the PP, already on your roster.

Jan 062011
 

The score of a game influences how a team plays.  When a team is trailing they play a more aggressive offensive game, when they are up a goal or more, they play a more defensive game.  The question I answer today is, how does score influence a teams save percentage.

To answer this question I looked at the past 3 seasons of 5v5 even strength save percentage data when the score is tied, when the team is up by a goal, when the team is up by 2 or more goals, when the team is down a goal and when the team is down by 2 or more goals.  For each team and score category I have a data point for 2007-08, 2008-09, 2009-10 as well as a three year average (2007-10).  For each score category I sorted from lowest to highest save percentage and then plotted them on one chart and got the following:

As you can see, when the game is tied generally produces higher save percentages than when a team is leading or trailing and when a team is trailing their save percentages are at their worst.  This is probably not surprising as a team will open up its game in hopes of creating offense but also puts them at risk defensively.  Now, what that table doesn’t tell us is if all teams experience the same score effects or, for whatever reason, do some teams actually have improved save percentages when trailing or leading.  The following chart shows each teams 3 year save percentage by score ordered from lowest 5v5 game tied save percentage.

The majority of teams have the majority of their leading or trailing save percentages below the game tied save percentages but there are a number of occassions where that doesn’t occur and they are mostly related to up2 or up2+ save percentages.  The only teams that had a down1 or down2+ save percentage above game tied save percentage were:

  1. Dallas – Down1: 92.51% vs Tied: 91.74%
  2. Detroit – Down1: 93.05% vs Tied: 92.16%
  3. Pittsburgh: Down2+: 92.87% vs Tied: 92.78%
  4. Minnesota:  Down2+: 93.21% vs Tied: 92.89%
  5. Florida: Down1: 93.92% vs Tied: 93.23%

On average, teams had their down 1 goal save percentage 1.3% lower than their game tied save percentage and their down 2+ goal save percentage 1.90% lower than their game tied save percentage.  The average team save percentage at 5v5 tied is 92.7% vs 91.4% down a goal, 90.8% down 2+ goals, 92.2% up a goal and 92.1% up 2 goals.  Tailing can have a sizable negative impact on save percentage where as leading can have a minor negative impact.

So what does this mean?  It means we need to be careful when evaluating goalies (and probably shooters to some extent) based on save percentage (special team effects) or even 5v5 even strength save percentage because the game situations a goalie has been exposed to will influence the goalies save percentage.  A goalie on a weak team will have his save percentage lowered simply because his team is going to be trailing more often and be forced to take chances to create offense and thus he will be exposed to tougher shots where as a goalie on a good team who leads the game more than they trail a lot will not face as many tough shots.

One interesting thing I noticed while doing all this was the Toronto Maple Leafs up by a single goal performance over the last 3 seasons.  While they were middle of the pack 5v5 game tied (16th in 3 year 5v5 game tied save percentage), they were downright horrific when they got up a goal.  They just couldn’t hold a lead.  The three worst single season save percentages when up a goal were the 2009-10 Leafs, 2008-09 Leafs, and the 2007-08 Leafs so they were three for three there.  Over the course of the past 3 seasons the Leafs posted an 88.4 save percentage when up a goal which was 3.44 standard deviations from the mean.  Next worse what the Ottawa Senators who were well ahead of them at 90.8, a mere 1.23 standard deviations from the mean.  The good news for Leaf fans is their 5v5 up a goal save percentage is much better this year: 95.6% (better than any team in any of the last 3 seasons), 97.2 for Gustavsson and 93.9% for Giguere so they are much better at maintaining the lead.  Unfortunately this season they can’t score well enough to get them a lead to protect.

Dec 162010
 

In the Hockey Statistical Analysis world Tomas Vokoun is an interesting case study because depending on how he gets evaluated he either shows up as an very good goalie or in some cases a true elite goalie in the NHL.  Most ways we evaluate goalies has to do with save percentages.  We either look at overall save percentage or even strength save percentage or even even strength game tied save percentage.  Under all of these scenarios Vokoun excels to various degrees.  A recent Behind the Net Hockey Blog post asked several hockey statistic analysts to discuss “elite goalies” and Tomas Vokoun’s name came up frequently.  What is dumbfounding to me is Vokoun’s record because his won-loss record (79-80-25) is notably worse over the past 3 seasons than his backups (32-22-8).  That can’t be a sign of an elite goalie, even if his backups have been relatively good (i.e. Craig Anderson).  One may postulate it is due to facing tougher competition as backup goalies often get the to play against weaker teams or one may postulate it is just due to bad luck.  Or maybe, he just isn’t a great goalie.

Since shots totals and shooting/save percentage is often affected by game score I’ll focus on 5v5 even strength game tied statistics to balance everything out.  Over the last 3 seasons (2007-08 to 2009-10) there are 35 goalies with 1500 or more 5v5 game tied minutes.  Of these goalies, Tomas Vokoun ranks 8th in 5v5 game tied save percentage which may not be elite, but still very good.  Jonas Hiller tops the list with a .942 save % with Vokoun at .933 and Chris Osgood trails the list with a .906 save %.  So, Vokoun looks pretty good.

But, Tomas Vokoun ranks just 23rd in goals against average which isn’t great and probably average at best.  Those who are in love with fenwick numbers will note that Vokoun has the second highest fenwick against of any goalies with 1500+ 5v5 tied minutes and he gives up so many goals because Florida gives up so many shots and scoring chances.  Of course, I believe that not all shots against are equal and shot totals can be influenced by style of play as much as talent.  If you don’t believe style of play affects shot totals and scoring chances, ask yourself why there are score effects on shot/corsi totals?  The answer is depending on the score, teams play differently.  But teams play differently when the score is tied as well.  Some teams play a defense first style, even when game is tied, and others play a more wide open offensive style.  Florida, without any true elite offensive stars, probably plays more of a defensive game which would naturally lead to more shots against, but not necessarily more quality scoring chances against.

So yes, Florida gives up a lot of shots, but how good is Tomas Vokoun’s competition really.  He does play in the weakest division in the NHL and yet he can’t produce a good won-loss record.  Just looking at Vokoun’s opposition, his opponents rank dead last in goals for per 20 minutes so compared to other goalies he is playing against relatively weak opponents offensively.  His oppositions GF% (goals for / goals for + against) is also fourth worst so overall so he plays against very weak opposition in terms of scoring goals and stopping goals.  For those who prefer Fenwick, his opposition has a FF% (fenwick for / fenwick for + against) of .499, good for 27th among the 35 goalies.  So his opposition isn’t good and his performance in goals against average isn’t good either.  That isn’t a good combination if you want to be considered an elite level goalie.

How about a direct comparison with his backups.  In 2007-08 his goals against average per 20 minutes was significantly worse than Craig Anderson’s (0.949 for Vokoun, 0.538 for Anderson) while Anderson’s opponents had a slightly better goals for per 20 minutes (0.678 vs 0.671).  In 2008-09 Vokoun had a much better season giving up 0.697 goals per 20 minutes compared to Anderson’s 0.896 though Anderson played against slightly better offensive competition.  In 2009-10 Vokoun had a much better goals against than Clemmensen (0.621 vs 1.058) but played against weaker competition as well (OppGF20 of .714 vs 0.743 for Clemmensen’s opponents).  Generally speaking Tomas Vokoun had a very weak 2007-08 season but much better 2008-09 and 2009-10 seasons even though he always seemed to play against weaker offensive opponents.

In terms of my Hockey Analysis Ratings, Tomas Vokoun ranked 16th out of 35 goalies in 2007-10 HARD and 18th in 2007-10 HARD+ rankings.  Middle of the pack.  The seasonal breakdown positioned him 35th of 38 in HARD+ for goalies with 500+ minutes in 2007-08, 19th of 35 in 2008-09, and 6th of 37 in 2009-10.  So far this season he is closer to the bottom again.

Is Tomas Vokoun an elite goalie, or even great goalie?  Probably not.  He just posts good save percentages because his team gives up a lot of shots, but not necessarily quality scoring chances, and he plays against weak offensive competition.

Dec 152010
 

I have been pretty quiet here recently not because of a lack of things I want to write about but because I needed to get my stats site up and running first so I can reference it in my writings.  Plus, getting my stats site up has been on my todo list for a real long time.  There will be a lot more stats to come including my with/against on ice pairing stats which I had up a season or two ago and many of you found interesting as well as team stats but for now let me explain what is there.

What you will find there now is my player rating system which produces the following ratings:

HARD – Hockey Analysis Rating – Defense

HARO – Hockey Analysis Rating – Offense

HART – Hockey Analysis Rating – Total

HARD+ – Hockey Analysis Rating – Defense

HARO+ – Hockey Analysis Rating – Offense

HART+ – Hockey Analysis Rating – Total

HARD is the defensive rating and is calculated by taking expected goals against while on the ice and dividing it by actual goals against while on the ice.  The expected goals against is calculated by taking the average of a players team mates goals against per 20 minutes (TMGA20) and averaging it with the players opposition goals for per 20 minutes (OppGF20).  Similarly HARO is calculated by taking a players actual goals for while on the ice and dividing it by the expected goals against while on the ice.  For both, a rating above 1.00 means that the player helped the team perform better than expected when he was on the ice where as a rating below 1.00 means the player hurt the teams performance when he was on the ice.  HART is just an average of HARD and HARO.

HARD+, HARO+ and HART+ are enhanced ratings which result from an iterative process that iteratively feeds HARD and HARO ratings into an algorithm to refine the ratings.  For the most part this iterative process produced a nice stable state but sometimes the algorithm goes haywire and things fail (i.e. for a particular season or seasons).  For this reason I am calling the + ratings experimental but if you don’t see anything wacky (i.e. large differences in every players ratings) they should be considered reliable and probably better ratings than the straight HARD, HARO and HART ratings.  Anything better than 1.00 should be considered better than the average player and anything less than 1.00 should be considered below average.

Continue reading »

Dec 032010
 

(Updated to include 3 seasons of data as I now realize that more luck data was available)

The other day there was a post on the Behind the Net Blog which used betting odds to estimate how lucky a team was during the 2009-10 season.  In many ways it is quite an ingenious way to evaluate a teams luck and I recommend those who have not read it go take a look.  Last night I was watching, sadly, the Leafs-Oilers game and thinking about luck in a hockey game and whether a team has any control over the luck they experience.   It got me thinking, does a team which controls the flow of the play mean that team is more likely to have more ‘good luck’ stuff happen to them than ‘bad luck’ stuff.

I defined luck as being how many standard deviations their actual point totals were from their expected point totals as defined in the document referenced in the Behind the Net blog post and in an updated document with 4 years of data.  I have only included 3 seasons in this analysis since I have only been working with 3 seasons of data recently and I was too lazy to go back and calculate a fourth season right now.

The most used stat to indicate how well a team controls the play is corsi or fenwick percentage which is basically the number of shots a team directs at the goal divided by the number of shots that they and their opponents teams directed at the goal.  I’ll be using Fenwick % here which includes shots and missed shots but not blocked shots.  So how does Fenwick % correlate with luck?

The correlation is fairly low but a correlation exists.  Maybe good teams can generate their own luck.  Here is a table of a teams luck and fenwick% for 2009-10.

Team Luck Fen%
Chicago Blackhawks 0.777 0.578
Detroit Red Wings 0.395 0.541
Boston Bruins -0.534 0.536
Pittsburgh Penguins -0.156 0.530
Toronto Maple Leafs -1.282 0.528
New Jersey Devils 0.459 0.522
St. Louis Blues 0.186 0.519
Phoenix Coyotes 2.092 0.515
Nashville Predators 1.225 0.514
Calgary Flames -0.590 0.513
Washington Capitals 1.883 0.512
San Jose Sharks 1.020 0.512
Philadelphia Flyers -1.157 0.511
Ottawa Senators 0.083 0.508
Los Angeles Kings 1.040 0.498
Buffalo Sabres 0.302 0.496
Atlanta Thrashers -0.347 0.496
New York Rangers -0.753 0.495
Vancouver Canucks 0.471 0.495
Carolina Hurricanes -0.555 0.491
New York Islanders -0.201 0.490
Columbus Blue Jackets -0.855 0.488
Dallas Stars -0.212 0.480
Anaheim Ducks -0.087 0.467
Tampa Bay Lightning -0.604 0.466
Florida Panthers -0.726 0.465
Montreal Canadiens 0.052 0.464
Minnesota Wild -0.486 0.459
Colorado Avalanche 0.599 0.449
Edmonton Oilers -1.993 0.446

When I was looking through the table something caught my attention.  Of the bottom 15 teams in Fenwick%, only four teams had positive luck.  These were Buffalo, Vancouver, Montreal and Colorado.  Generally speaking, these four teams had good to very good goaltending.  Of the top 15 teams in Fenwick%, only five teams had negative luck.  These were Boston, Pittsburgh, Toronto, Calgary and Philadelphia.  Boston and Calgary had good to very good goaltending (especially once Boston switched mostly to Rask) but Philadelphia, Pittsburgh and Toronto had mediocre to poor goaltending.  That got me to wondering whether goaltending correlated with luck at all so I took a look at the correlation between 5v5 game tied shooting and save percentages with luck.

Like fenwick%, there is an indication of a small correlation between shooting percentage and luck and there is a bit more of a correlation with save percentage.  Next I looked at combining all three factors.  Initially I was going to look at combining all three through some sort of average but then decided to look at goals for percentage instead (goals for divided by goals for plus goals against) since that basically encompasses everything anyway and we find that combined we get a relatively strong correlation with luck.

Now we are getting into correlation that might actually mean something, but what does it all mean?  To be honest, I am not sure.  Regardless of what ‘skill’ we look at there does seem to be a small positive correlation between how good a team is and how good their luck is (as calculated from the betting lines).  Does this mean that a bad team and especially a team with bad goaltending opens itself up to more bad luck than good teams or teams with good goaltending, or does it mean that luck manifests itself mostly in bad goals against or does it simply mean that the people who bet on hockey games trend towards betting the underdog which would push their expected winning percentage up and good teams expected winning percentage down which would result in a poor estimation of luck?  I am not sure how you determine what the exact cause of the correlation is but if it is the latter I have a word of advice, always bet the favourite.

Nov 222010
 

There are two things that must occur to score a goal.  The first way is to get an opportunity to score and the second is to capitalize on that opportunity to score.  There are a number of statistics that we can use as a proxy for opportunity to score but one of the most common is Fenwick numbers which are shots + missed shots (some call this Corsi but I define Corsi as shots + missed shots + blocked shots).  We can then define the ability to cash in on opportunities as shooting percentage, or in this case fenwick shooting percentage.  So let me define the following:

Opportunity Generation = Fenwick shots per 20 minutes of ice time.

Capitalization Ability = Fenwick Shooting Percentage = Goals Scored / Fenwick shots

So the question I pose today is this:  What is more important in scoring goals, generating opportunities or the ability to capitalize on those opportunities.  To answer this I calculated each teams Fenwick per 20 minutes (opportunity generation) and each teams Fenwick Shooting Percentage (capitalization ability) and compared them to the number of goals they generated per 20 minutes of ice time and I did this for each of the past three seasons (I only considered even strength five on five data).  I also did this for both the offensive and defensive ends of the ice for a total of 90 data points offensively and defensively.

First for the offensive end of the game:

As you can see, shooting percentage (opportunity capitalization) has a much stronger relationship with scoring goals than getting shots (opportunity generation).  What about the defensive end of the game?

Again, opposition capitalization rates are much more correlated with scoring goals than opportunity generation.  In fact opportunity generation appears to have no correlation with giving up goals at.

The conclusion we can draw from these four charts is when it comes to scoring goals, having the ability to capitalize on opportunities (shots) is far more important than having the ability to generate opportunities (getting shots).  Controlling the play and generating shots does not mean you’ll score goals (just ask any Maple Leaf fan), having the talent to capitalize on those opportunities is what matters most.  From my perspective, this means the usefulness of ‘Corsi Analysis’ to be minimal, at least for the purpose of evaluating players and teams.  For evaluating goaltender workload, as it was initially intended by its originator former NHL goalie and Buffalo goalie coach Jim Corsi, it still has merit.

Nov 162010
 

Every year we hear Leaf fans making the argument that they are a patient bunch and are willing to wait out a lengthy 5 year rebuilding plan and yet a mere 15 or so games into the season (and barely 40 games into the overhaul of the group of forwards) I am reading stories about Leaf fans wanting to fire Ron Wilson, some are jumping all over GM Brian Burke calling him a failure and some are even pointing out that this is just more of the same old thing that has been happening in Toronto the past 40 seasons.  I have even witnessed people who bemoaned the demotion of Nazem Kadri after last seasons training camp claiming Kadri was ready based on a good pre-season and now bemoaning his promotion 15 or so games into this season as Kadri isn’t ready for the NHL yet.

With this post I am calling on Leaf fans to just chill and give the process a chance.  I understand your dismay at how the Leafs have played the past 10 or so games, but show a little patience that you always claimed you had and if you are honest with yourselves you will realize that there is real progress here regardless of record.  This is not the same team as last year and in fact it is vastly different, and for the better.  Here are some things we need to remember.

  1. This is a very young team, especially at forward.  Kessel, Bozak, Kulemin, Caputi, Kadri, and Versteeg are all age 24 and younger and with youth you will experience ups and downs as they develop.  They need time to develop and we need to be patient with them.  Players don’t become reliable veterans overnight.
  2. The goaltending, while still not great, is improved and as a result the Leafs have been in almost every game they have played this season and few losses can be directly blamed on the goaltending.  That’s a far cry from the past couple seasons when you can pretty much turn the game off after one period for a significant portion of the games largely due to horrific goaltending.  Plus their prospect goalies look promising as well.
  3. The defense has actually been pretty good.  They are among the league leaders in fewest shots against and combined with their decent goaltending they are middle of the pact in goals against average.  That is a huge improvement from one year ago.
  4. Most importantly we need to remember that this is still not the team Burke wants.  He isn’t finished the rebuild yet, especially the forwards. Specifically, he is looking for at least one, maybe two, offensive forwards, preferably with size, for the top 2 lines.  There may be other changes he needs to make as well as even the best laid plans need to be tweaked from time to time.  We need to give him some more time to finish the job.

I understand the concern about the team and its fortunes.  I share that concern.  I don’t like watching the team lost and I certainly don’t know how Burke’s plan will continue to unfold.  Truth is, Brian Burke feels the same and doesn’t know either.  Maybe Bozak and Kadri never develop into useful NHLers.  Maybe Burke can never find another dominant offensive forward to go with Kessel.  Maybe Gustavsson, Rynnas, etc. never develop into reliable NHL goalies and the Leafs continue to flounder with sub-par goaltending.  I don’t know how it will all unfold, but we need to at least give Burke some time to finish his rebuild and then we can evaluate him fairly.