Drance Numbers is the silly research wing of PITB. While Messrs. Wagner and Mooney blog nationally and solve mysteries, Drance Numbers will look into the minutiae of quantifiable NHL data and bore you with it every Friday.
There’s no sugarcoating it, Roberto Luongo has struggled out of the gate this season. This has exacerbated what most agree is a “toxic relationship” between Canucks supporters and the man they used to call “#Luongold”. Though Luongo has his supporters (I tend to be one of them), many Canucks fans tear at “Luuu” over every soft goal like vultures. Vancouver sports fans are “concerned” about their Vezina Nominee goaltender, and as we saw this week, professional goalie scouts are as well.
I’ve worked closely with Justin Goldman (AKA The Goalie Guild) in the past, and really respect his opinions and observations. I recently received a complimentary copy of Goldman’s thorough and informative Goaltenders Style-Guide, and though it describes Luongo as among the “most intimidating and positionally sound” goaltenders in the NHL, it questions “what’s right between his ears.” Goldman, clearly, is in the camp that believes Luongo has issues with the mental aspect of his game, and that the “mental side” gets in the way of Luongo playing up to his enormous talent level.
After the Philadelphia game on Wednesday night, Goldman recorded an extraordinarily critical and worrisome audio blog-post about Luongo’s performance over the past couple of seasons. What Goldman seems to believe is that Luongo has regressed as a goaltender, partly as a result of the enormous pressure he’s under playing in Vancouver, and partly because of over-coaching. Says Goldman, addressing a pet peeve of many a Luongo skeptic: “When [Luongo] scrambles or has to rely on his natural instincts and reactions, what does he do? He falls on his face half of the time.”
One of the major issues with analyzing Roberto Luongo statistically is that what his critics point to as his “flaws” or “issues” are difficult to measure with numbers. A player’s “issues with the mental aspects of the game” don’t show up on a boxscore, and can’t be quantified easily (though I’m about to make an cursory effort).
One thing that mystifies me about Luongo’s numbers, are his home and road splits. While it’s not uncommon for goaltenders to perform better at home than on the road – Luongo’s save percentage has been consistently .020% better at home than on the road over the past three seasons. I checked the splits of similar goaltenders and found that the degree and consistency of this deviation is pretty rare, so I figured I’d look into it further.
Hockey Prospectus has begun recording a goaltending stat called “Quality Starts,” over the past few seasons. Quality Starts are borrowed from baseball (where they measure pitching) and are expressed as a percentage. You can read more about it here, but basically a Quality Start for a goaltender is a game in which his save percentage is higher than .913%, or a game in which he allows two or fewer goals against. The idea behind “Quality Starts” is that they are more insightful and useful than simply counting wins or overall SV% because they measure how often a goaltender gives his team a good chance of coming away with two points.
What I’m going to add into the equation is what we’ll call “Blown Up Percentage,” which, will track the number of times a goaltender was so sieve-like that his team had functionally no chance of victory. I’ve defined a performance in which a goaltender gets “blown up” as one in which his save percentage is lower than .850%, or in which he allows five goals-against, while facing fewer than 40 shots.
In particular what I’m interested in, is seeing whether or not Luongo’s “Blown up Percentage” (BU%) and “Quality Start Percentage” (QS%) reflect what we see in his overall save percentage. Though other goalies may not exhibit the same level of deviation between their performance on the road and at home in terms of overall save percentage – do their BU% and QS% slip on the road compared to their performance at home?
I compared Luongo’s numbers over the past three seasons with 4 other goaltenders whom most would consider to be very good at their jobs: Tim Thomas, Henrik Lundqvist, Ilya Bryzgalov and Ryan Miller. All five are veterans, work-horses and are awesome at blocking pucks, so they suit our purposes well, even if this sample isn’t large enough to be comprehensive. So does Luongo’s lack of “mental toughness” in fact make him more likely to “blow up” on the road than comparable NHL goaltenders?
The answer, in short, is no. You can see my full numbers here if you so wish, but all five of these inarguably elite NHL goaltenders exhibited a pretty similar trend over the past three season. Generally speaking, all five goalies were more likely to post a quality start at home than on the road, and were significantly more likely to get “blown up” on the road than at home.
Apparently home-ice advantage is important.
This is an admittedly superficial look at home and away splits for QS%, but I’d suggest that this is a topic that warrants further examination. In particular, road-teams in hockey tend to be called for 20% more penalties than home-teams, so I’d be interested to see how special teams impact these findings.
But before taking to Twitter to admonish an Olympic gold-medalist, it’s worth bearing in mind that some of the most talented goaltenders in the world’s best professional hockey league get “blown up” on occasion.Tags: drance numbers, mental toughness, Roberto Luongo