Sunday, July 19, 2015

An In-Depth Robin Lehner Trade Analysis

Source: Jay Kopinski/Icon SMI
Also submitted as a fanpost on Die By The Blade.

When the news first broke that the Buffalo Sabres had traded the 21st overall pick in the 2015 NHL Entry Draft in exchange for Robin Lehner and David Legwand from the Ottawa Senators, a good portion of Sabres nation freaked out. Not only were the Sabres trading away a 1st round pick in a draft that many have been labeling as the deepest since 2003, they were also acquiring a starting goaltender that many fans didn't even consider to be the best option available on the trade market (myself included). But despite his struggles in Ottawa over the past two seasons, there's no denying that the soon-to-be 24-year old has excellent long-term potential.

Now that the dust has settled, the question I want to answer is whether Tim Murray made the best move by acquiring Robin Lehner. To evaluate this, I'm comparing Lehner to the other goalies that were traded and had been previously linked to the Sabres (Cam TalbotEddie LackMartin Jones and the negotiating rights for Antti Niemi) through the following lenses: projected performance, the cost of the draft pick(s) that each goaltender was exchanged for, and the value of each goaltender's contract.

Projected Performance

Let's start with the caveat that the easiest thing to predict about goaltenders' performance from season to season is that it's very unpredictable, though the more shots a goaltender has faced over the course of his career the better we are able to project his performance in the future. There's also the question of whether 5v5 / Even-Strength Save % is the best metric for evaluating goaltender performance, as well as the accuracy of shot location data for High, Medium and Low Danger Zone opportunities from War-on-Ice that will play a large part in this analysis. So given the limited tools available, how does Lehner stack up against the other recently traded goalies? 

A few days before the trade frenzy, the phenomenal InGoal Magazine ran a piece breaking down Talbot, Lack and Lehner by Danger Zone (or DZ). In summary, the article determined that Talbot was the most preferable of the three goalies, followed by Lack and then Lehner. By comparing all three goaltenders' Career Save %s by DZ and how that compared to the volume of shots and quality of goaltenders that Buffalo endured last season, the article estimated that Talbot would have saved the Sabres an estimated 36 goals last season (or an additional 6 wins, applying a thumb rule developed by Eric Tulsky a few years ago). As for Lack and Lehner, they would have respectively saved just 12 and 2 more goals than the Buffalo Sabres' 2014-15 goaltending battery of Michal Neuvirth, Jhonas Enroth, Anders Lindback, Matt Hackett and Andrey Makarov managed to stop. 

But when it comes to evaluating goaltenders' desirability based on past performance alone, Lehner should get a lot more benefit of the doubt than the article gives him for a few different reasons. First off, part of Lehner's performance likely can be explained by Paul MacLean's system simply not being the best fit for him, a possibility raised by both InGoal Editor / goaltending guru Kevin Woodley and Lehner himself. As Woodley notes in a seperate piece:
"[Lehner] has not progressed technically during his time with the Senators. That’s not shocking given the way Ottawa’s goalies play, with an emphasis on more aggressive positioning than in many other places and more flow and movement as a result."
Age also benefits Lehner favorably relative to the other recently traded goalies, as the soon-to-be 24-year old is just now entering the part of his career where most goaltenders peak. Conversely, Talbot and Lack are already both 27, still close to their primes but at the start of the gradual drop-off. Another theory that could also work in Lehner's favor is the idea that he will thrive now that he's out of Craig Anderson's shadow and will be the undisputed starter in Buffalo, ahead of Chad Johnson. This would be similar to how Sergei Bobrovsky showed flashes of potential in Philadelphia but didn't blossom until he was traded to Columbus and handed the starting job.

While Lehner's Career 5v5 Save % is disconcerting when compared to the other goaltending candidates (91.77%, or .4% below the league average from 2007-15 per data from War-on-Ice), a deeper look into Lehner's performance by DZ tells a different story:


When predicting future goaltending success, High DZ saves have been found to be the most correlated with overall success, while Medium DZ saves have some correlation and Low DZ saves have virtually none at all. Given the relatively large variance of High DZ Save % for 49 goalies that faced at least 3,000 shots from 2007-15, it's most likely that differentiable skill is surfacing in High DZ Save %, which is the one DZ area that Lehner comes out ahead of the league average (albeit in a pretty limited sample size). Conversely, Lehner's Low DZ Save % falls significantly below the 2007-15 average of 97.4%; since all but two goalies from 2007-15 had Career Low DZ Save %s within 97-98%, Lehner is a prime candidate to see his Low DZ Save % rise towards the league average over the next few seasons. To a lesser extent, we should also expect Lehner's significantly low Medium DZ Save % to rise towards the league average. Lehner also has a great opportunity to improve on his High DZ Save % due to his young age and the volume of work and development he will get this season.

While Lehner's career save percentages by DZ helps validate the idea that he was relatively unlucky during his time in Ottawa, some fans may still feel strongly that Martin Jones or Cam Talbot would have been better options. However, both goaltenders benefited from some luck in even smaller sample sizes than Lehner, with both Jones and Talbot accruing unsustainably High DZ Save %s on defensively stout teams during the peak years of their careers. Given that Cory Schneider has the best Career High DZ Save % of 86.09% from War-on-Ice's dataset and the only other goalies above 85% are Jonas Hiller, Tuukka Rask, Braden Holtby and Henrik Lundqvist, Jones (86.2%) and Talbot (88.3%) will almost certainly see their High DZ %s regress in San Jose and Edmonton, respectively. The question that is difficult to answer is how much regression we should expect each to experience over the next few seasons, and how their long-term performance will compare to Lehner.

To help evaluate this, I utilized a hockey version of baseball's Marcels forecasting system as developed by Garik16, which in turn is based off of Brian MacDonald's Bayesian approach to projecting goaltender performance. While the Marcels model is still very new and has its limitations (e.g., a below average goaltender is positively impacted by regression to the mean; it does not utilize Adjusted Save %s in its forecast), its use of regression and aging makes it the best available tool for projecting future performance. After refreshing and replicating Garik16's projections from February of 2015 for 5v5 Career Save %, I came up with the below ballpark values that we should see expect each goaltender to perform at over the next few seasons and compared it to their past performance:

I have a much more thorough examination of the Marcels methodology in a separate post. But it should be noted that the previous season's performance plays a considerable effect on how well a goaltender is expected to play in the future, so a significantly lucky or unlucky season the year before is going to have a large effect on the projection. Using the same weighting methodology following the 2012-13 season, Lehner would have been projected to be a long-term .924 5v5 goalie - i.e., where Talbot is now - but a variety of factors contributed to him being a .912 5v5 goalie the past two seasons.  Whether those factors were plain old bad luck or Lehner's initial success in the NHL (.938 5v5 goalie from 2011-13) being significantly higher than his actual ability will be played out in Buffalo this season.

One additional consideration that should be noted is that all the goaltenders in this analysis have switched teams, which could have an effect on projections. However, the odds that a new team will significantly impact any of the goaltenders' future performance are pretty low. Generally speaking, shot quality distribution for starting goaltenders has generally been found to only affect save percentage by 0.5% or less, while save percentages by shot attempt quantity has too much noise to claim that a higher workload has a positive or negative impact. So while I am particularly worried for Cam Talbot in Edmonton given the recent history there, individual talent and luck should be the two main factors driving future goaltender performance.

Speaking of luck, the role that it plays in goaltender save percentages and performance gives a lot of weight to the argument that the Sabres simply should've went for the goalie that was the best value. Knowing what we know about past performance and future projections, was the price that Buffalo paid to acquire Lehner worth giving up the 21st overall pick in the 2015 NHL Entry Level Draft?

Draft Pick Value

My initial reaction to the Robin Lehner trade was that Eddie Lack or Martin Jones would have been better trade options for the Sabres due to the relatively lower asking prices that Los Angeles and Vancouver would demand from Buffalo, as the Sabres were the only Eastern Conference team seeking a starter for the 2015-16 season. However, I was glad that Buffalo traded just the #21 pick to the Senators as opposed to #31 and #51, which Bryan Murray would have likely preferred based on his earlier comments. Additionally, I was glad that the #21 pick was used to acquire Lehner as opposed to an 18-year old goalie, which is an even riskier proposition in my opinion. So was I on point with my initial reaction that many Sabres fans likely shared?

For this analysis, I'll evaluate what the Sabres, Oilers, Sharks, Hurricanes and Stars respectively paid the Senators, Rangers, Canucks, Bruins and Sharks into a couple different draft pick valuation systems to help determine trade value. It should be noted that I'm only evaluating the Bruins' trade of Jones to San Jose, as the initial trade of Jones to the Bruins was part of a package the Kings used to acquire Milan Lucic. I also omitted David Legwand's inclusion in the Lehner trade from this analysis, as the team's current cap situation makes it easy for Buffalo to either keep or waive him at any point this season.

The first valuation system I utilized was developed by Scott Cullen of TSN and assigns each player selected from the 1990 to 2010 drafts a value of 1-10 as an indicator of his success, with 1 being a player that has played 10 NHL games or less and 10 being a 'Generational' player. Each draft slot is then given an average expected score based on past success of the players drafted in those spots alone. It should be noted that this system has a bunch of disclaimers that I dedicated a separate post to when it came to evaluating these trades (including my work around for valuing the Sharks' future first round pick, but more on that in a bit). However, what makes Cullen's methodology advantageous is it creates a ballpark value for each pick in the draft that can then be translated into in plain English, such that #1 overall pick is expected to be a 1st liner while the 21st is expected to fall somewhere between a Fringe (200-349 NHL games) and Regular (350+) NHLer.


The second valuation system I used was developed by Eric Tulsky, who looked at 46 draft pick trades from the 2006 to 2012 drafts to estimate the prices GMs had to pay to move up and down in the draft  them and placed it on a scale of 0-100 (similar to the NFL Draft's Value Board). As shown in the above graph, I mapped Tulsky's graph into an exponential equation that gives us an R^2 of over 96%, a near perfect fit outside of the Top 10. What separates these two systems is the end goal - Tulsky's is about the expected cost for moving up and down in the draft, while Cullen's is about the expected value of the player that you draft in those positions. 

While trading a first rounder for Lehner may have sounded bad initially, both systems have it as being superior to trading two second round picks. The only way trading #21 instead of #31 and #51 can be considered a loss for the Sabres is if the Avalanche would have demanded a lesser prospect than JT Compher  in the Ryan O'Reilly trade if #21 was still play (side note: I highly doubt Colorado makes the trade with Buffalo unless Nikita Zadorov is included, given their need for left handed defensemen). Additionally, Robin Lehner is well on his way to being a Regular NHLer, meaning Buffalo gave Ottawa fair value to get the goalie they considered to be the best on the market (from an in-division rival, no less).

Depending on the valuation system employed, different conclusions come out over who paid the higher price between Buffalo and Edmonton. While Tulsky's draft value board would indicate that the Oilers spent half the amount of draft capital than Buffalo did, the Oilers gave up about the same amount of expected NHL talent as the Sabres did according to Cullen's system. This is not an unreasonable conclusion: the odds that any one of the Rangers' three draft picks becomes a Regular NHLer are probably about as good that the player that ultimately went #21 to Ottawa, Colin White, does. Though more research should be done into this, a market inefficiency could exist in teams overvaluing position in the latter (4th through 7th) rounds, meaning that teams should be trying to move down as often as possible to gain additional picks once they are in the back nine of the draft.

What is also important to remember is when these trades occurred. While many hockey pundits thought Cam Talbot would be the first domino to fall, Buffalo made the first move before another team that lost out on Talbot would ante up to acquire Lehner. While Murray's aggressiveness means he didn't get the best value on the trade market (that distinction goes to Ron Francis), the Sabres avoided the fate of the Sharks. Having missed out on the other trade options and seeing their previous starter Antti Niemi' sign with Dallas after his negotiating rights were traded there, the Sharks were forced to pony up a 2016 1st round pick and a prospect for Jones. A future 1st first pick is a significantly higher risk than moving #21 given that teams that miss playoffs (which is definitely a possibility for the Sharks) will have three chances to move into the top of the draft starting next summer

In any scenario, the price that Hurricanes spent on Eddie Lack was the best value of the goalie trades, as Jim Benning had to settle for a 3rd round pick after shopping Lack for a 2nd rounder. Additionally, the price that Ron Francis paid for Eddie Lack is the same price that Tim Murray could have gotten Lack for, given Vancouver's preference to move him east (versus Calgary or Edmonton). What is not in Lack's favor is the fact that he has the worst Career High Danger Zone (DZ) Save % of the traded goalies, and is a strong candidate to see his Medium Save % regress back towards the mean. But Lack has also seeked out Lyle Mast to train with this summer, the founder of the Head Trajectory puck trucking philosophy for goaltenders that has been identified as one of the contributing factors to Devan Dubnyk's bounce back season. Should this training help Lack realize just some of the gains that Dubnyk made in High DZ Save % from 2013-14 (81.3%) to 2014-15 (85.8%), then the Lack trade could rank alongisde Noah Hanifin falling to #5 as the steal of the summer. Given that Lack (as well as Talbot) are entering contract years, great seasons will respectively force Carolina and Edmonton into tough contract decisions - and this is where Lehner's value to Buffalo really comes into play.

Contract Value

As stated before, the more shots a goaltender has faced over the course of his career, the better his future performance can be projected. Of the goaltenders traded this summer, only the soon-to-be 32-year old Antti Niemi had faced more career shots, and Dallas will be paying him $13.5M over the next three years to provide league average goaltending in a best case scenario. With Lack and Talbot, who are both set to be UFAs in 2016, Carolina and Edmonton will have just a few seasons worth of data to determine whether to extend them long term or not.

The Sabres and Sharks, meanwhile, will respectively have four and three seasons until their newly acquired goaltenders are eligible to be UFAs, giving both teams plenty of time for their goaltenders to get experience and for the two teams to make more informed decisions than the Hurricanes and Oilers will be able to next season. Though they both cost first round picks, the fact that Jones and Lehner both have high ceilings, are in their primes age-wise and are on $2.5-3M AAV contracts for the next few seasons makes them less risky bets in the long term (i.e., beyond next season) than Lack and Talbot. And in a worst case scenario that Lehner and/or Jones don't pan out, both will have relatively easy contracts to move on from as opposed to, say, the $10.4M tandem in Dallas, or what Talbot and Lack could hypothetically get paid if they have career years. The only other question left to answer is whether Buffalo made the right bet on Lehner.

Verdict

I had initially hoped that the Sabres would land Martin Jones, thinking he offered the best trade off between talent, youth, and cost to the Sabres. However, the fact that Jones was ultimately traded for a higher price has me thinking that Robin Lehner is a slightly better bet given he is two years younger than Jones and his recent run of bad luck should turn in Buffalo, as should Jones' good luck in San Jose. Additionally, Jones has just 1/3 of the body of work that Lehner has in the NHL. But what I am ultimately happy about is that the Sabres didn't acquire Talbot or Lack due to their upcoming contract situations nor a UFA goalie like Niemi or Karri Ramo, as average goaltending is readily available every summer. Great goaltending has to either be nurtured or acquired at a steep price (hence why Anaheim isn't pushing John Gibson or Frederik Andersen out the door). With no other goaltending prospects in the Sabres' pipeline being close to NHL-ready, Lehner provides the Sabres their best chance of developing a top 10 goaltender in the NHL within the next few seasons.

So I will trust that Tim Murray has done his homework on Lehner, recognizing the role bad luck has played thus far in his career, and did not acquire him simply because he's familiar with Lehner from his Ottawa days. I am also optimistic about the role Andrew Allen can play in Lehner's development, given his work with the Blackhawks' young goaltenders in Rockford and the fact Dan Bylsma hired him with Robin Lehner's development in mind. But even in a worse case scenario where Lehner does not pan out as hoped, his affordable contract would make it easy for Buffalo to move on from (and hey, the Lightning did have to go through Anders Lindback before they got to Ben Bishop and Andrei Vasilevskiy). When it comes to risk taking, I would rather see the Sabres swing for the fences in net than to be perpetually stuck in a state of goaltending mediocrity.  

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