Over the past ten years, the image of the ideal NHL defenseman has changed dramatically. The days of stay-at-home defensemen like Adam Foote being counted among the league's best are fading into the rearview mirror of NHL history, as teams have leaned towards quicker players adept at passing the puck to form the core of their bluelines.

Hulking enforcer defensemen are finding fewer and fewer spots on rosters, and big, slow bruisers like Luke Schenn are no longer taken in the top-five of NHL drafts. As recent Norris Trophy voting shows, flashy talents like Erik Karlsson and P.K. Subban are not solely viewed as "offensive defensemen," but truly as the best that the position has to offer.

It's tough to say if the rise of advanced analytics in hockey caused this shift in perception or merely contributed to its inevitable rise, but it's undeniable that stats tend to favor defensemen who are capable of making a strong first pass out of their own zone and can carry the puck up ice with speed. Because a defenseman with those skills has more personal control over the direction of play, he usually does a good job of ensuring that puck possession is in his team's favor while he is on the ice.

On the other hand, statistics like blocked shots and hits -- formerly the lifeblood of a stay-at-home defenseman -- are dismissed if not outright scorned by many advanced statistics acolytes. The thought process is that both by nature occur only when the team lacks possession of the puck. Both actions (especially blocked shots) are better than the alternative, but if a defenseman is racking up high totals of each, his team most likely does not have the puck very often when he is on the ice.

But there are exceptions. Los Angeles' Jake Muzzin is ninth in the NHL in hits this season, and he has always performed well by advanced metrics. Mark Giordano is fifth in blocked shots, and he is rightfully considered one of the NHL's best defensemen. Still, both Muzzin and Giordano are accurately considered to be elite at transitioning play from defense to offense through smart passes and great skating, making their stellar possession statistics easy to accept.

Radko Gudas, on the other hand, clearly lacks elite puck skills via the eye test and ranks in the top-25 in the NHL in both hits (second) and blocked shots (22nd). At first glance, he looks like the quintessential old-school, physical defenseman who specializes in goal prevention rather than puck possession, and one who would be mediocre at best by advanced stats. His record filled with hits of questionable legality only serves to further that perception.

Yet Gudas has actually posted fantastic metrics this season when it comes to driving play. The Flyers are winning the even strength shot attempts battle by a substantial amount with Radko Gudas on the ice.

So what makes Gudas so unique? How has he been able to check so many of the boxes of a stay-at-home blueliner, yet still drive play like a puck-mover?

Gudas' advanced stats are among the league's best

Before we delve into the specifics of Radko Gudas' playing style, let's take a look at his advanced metrics this season. Among all Flyers blueliners, Gudas has the best on-ice shot attempt differential (Corsi), both from a raw percentage standpoint and relative to his teammates. And with Michael Del Zotto out for the season and Evgeny Medvedev relegated to a seemingly-permanent spot in the press box, Gudas is the best possession defenseman left on the Flyers by far.

All metrics are score-adjusted via War-On-Ice.com.

But Gudas isn't just posting a strong season on the Flyers by the advanced metrics. He ranks ninth in the entire NHL among defensemen in Corsi relative to his teammates.

All metrics are score-adjusted via War-On-Ice.com and limited to defensemen with more than 700 5-on-5 minutes.

Most striking is the murderer's row that lines up behind Gudas. Drew Doughty and John Klingberg both have been discussed as candidates for this year's Norris Trophy given to the league's best defenseman, while Giordano and Byfuglien are universally accepted as elite blueliners. With a little over a week left in the NHL season, Gudas has outperformed them all in terms of driving play relative to his teammates.

Rethinking Radko

The general perception surrounding Radko Gudas is that of a defensively-oriented, physical player. There is evidence to support this description -- his high hit totals, low scoring numbers, and the fact that Flyers head coach Dave Hakstol uses him on the penalty kill and in late-game situations.

But this is not the most complete way to understand what Gudas brings to the table. When it comes to even strength shot creation and shot prevention, Radko Gudas is markedly better at the former. Despite his mediocre puck skills and lack of high-end skating speed, Gudas actually is better at creating offense than preventing it.

Gudas is in his fourth NHL season. In those four seasons, he posted a promising rookie year by possession metrics, fell to solidly negative in years two and three, and then took his massive step forward this season. But in all four years (even his bad ones), Gudas' teams created more shot attempts with him on the ice than with him on the bench. Essentially, Gudas makes his teams more efficient offensively when he plays hockey.

Season On-Ice Shot Attempts Per 60 Off-Ice Shot Attempts Per 60 Differential Per 60 2015-16 64.84 55.91 +8.93 2014-15 64.90 58.68 +6.22 2013-14 58.28 57.56 +0.72 2012-13 62.19 50.01 +12.18

All metrics are adjusted for score, zone and venue via Corsica.Hockey.

The offensive metrics of Radko Gudas have always been strong. What separates his effective seasons from his ineffective ones has been his defensive play. Basically, Gudas' two down years were a result of his inability to stop the opposition from blasting shot attempts at his goaltender. If Gudas has an exploitable weakness, it's actually on the defensive side.

Season On-Ice Shot Attempts Allowed Per 60 Off-Ice Shot Attempts Allowed Per 60 Differential Per 60 2015-16 57.19 61.93 -4.74 2014-15 58.78 46.67 +12.11 2013-14 60.30 51.86 +8.44 2012-13 54.48 61.84 -7.36

All metrics are adjusted for score, zone and venue via Corsica.Hockey.

Remember that when looking at shot suppression, you want a player to have a negative Differential Per 60 -- that means that his team allows fewer shot attempts when he is on the ice versus when he isn't playing. By that measure, Radko Gudas has posted two strong defensive seasons (this year and his rookie year) and two bad ones.

These statistics give us a high-level view of the general reasons a player like Radko Gudas succeeds or fails. In this case, his offensive game seems to be relatively stable, and it's defensive play that determines whether he will be the good or the bad Gudas in a given year. But what on-ice shot attempt differentials fail to highlight is the how. How is Radko Gudas effective offensively despite a skillset that would hint otherwise? And most important, why is Gudas good defensively in some seasons and bad defensively in others?

Gudas: secret offensive dynamo

We've already been able to determine that Radko Gudas helps his team to generate offense, since his teams take more shots with him on the ice than with him off it. However, that does nothing to explain what skills Gudas brings to the table that allow his teams to take more shots when he plays. To do that, it becomes necessary to dive even deeper, and analyze Gudas' individual metrics.

Those metrics paint a picture of a defenseman far more adept at creating offense than the eye test would first lead one to believe. First, let's look at individual offensive zone entries, or the ability of a player to push the puck into the attacking zone. Gudas' negative reputation as a slow defenseman with stone hands would make you think that he rarely generates entries on his own, and that when he does, it's almost never with possession of the puck. But that is not the case.

Defenseman Controlled Entry Percentage Entries Per 60 Shayne Gostisbehere 46.43% 12.22 Mark Streit 45.22% 8.00 Radko Gudas 41.67% 6.55 Michael Del Zotto 38.13% 8.93 Evgeny Medvedev 37.76% 8.61 Andrew MacDonald 32.00% 4.51 Luke Schenn 29.79% 6.41 Brandon Manning 27.27% 8.51 Nick Schultz 17.70% 6.50

Shayne Gostisbehere is clearly in a tier of his own, as he personally generates far more entries than any other Philadelphia defenseman while also leading the blueline in controlled entry percentage. But Gudas' peers are not stay-at-home guys like Schultz, Manning and MacDonald. His metrics are more in line with Mark Streit, Michael Del Zotto and Evgeny Medvedev, all viewed as players possessing above-average offensive skills.

Not only is Gudas surprisingly adept at getting the puck into the offensive zone, he actively helps out his forwards in terms of shot generation once on the attack. The Czech defenseman leads all Flyers blueliners with 6.16 shots on goal per sixty minutes of even strength hockey.

He's actually the third-best defenseman in the entire NHL when it comes to generating shot attempts at even strength, as well. Gudas' 14.14 individual Corsi (total shot attempts taken by Gudas) per 60 ranks behind only Brent Burns and Johnny Boychuk, and just ahead of offensive weapons Erik Karlsson and Jake Muzzin.

When accounting for Gudas' ability to drive the puck into the offensive zone and then take lots of shots once the puck is there, it's obvious that he is improving his team's offensive efficiency the old-fashioned way -- by doing it himself.

Cracking the code of Gudas' defensive inconsistency

Radko Gudas has been above-average throughout his entire NHL career in helping his team to generate offense, because he takes an active role in moving the puck up ice and directing shots at the net. His shot suppression abilities, on the other hand, have been far more erratic.

After a strong defensive rookie season, Gudas' suppression abilities regressed in his final two years in Tampa. Now with the Flyers, Gudas is yet again preventing opponents from creating shots on the attack. So what changed this season for Gudas? Luckily, we can use two sets of manually-tracked data to answer this question -- my entry and exit data from this season, and Corey Sznajder's data from the All Three Zones project of 2013-14.

Gudas played only 31 games in 2014-15 before suffering a knee injury, so we actually have manually-tracked microstat data for Gudas' last two full seasons of hockey. Microstat tracking focuses on two key areas of defensive play -- the ability of a defenseman to prevent opposing forwards from entering his zone with possession of the puck, and also the defenseman's contributions in getting the puck out of the zone entirely.

Let's look at the latter first. While Corey and I track similar categories when looking at zone exits, it's best not to compare the specific percentages of the two seasons, due to the existence of tracker bias. Still, looking at Gudas' ranking among his teammates in both seasons should give us insight into his effectiveness at moving the puck out of the defensive zone.

Year Successful Exit Percentage Rank Controlled Exit Percentage Rank Turnover Percentage Rank Gudas in 15/16 (Philadelphia) 8th best (out of 9) 8th best (out of 9) Worst (out of 9) Gudas in 13/14 (Tampa Bay) 4th best (out of 7) 5th best (out of 7) 2nd worst (out of 7)

Ranks only include defensemen with at least 300 5-on-5 minutes. Exit metrics from this season are accurate through the All-Star break.

Two things are clear by looking at this chart. First, defensive zone exits have never been a strength of Radko Gudas' game. In both his good shot suppression season with Philadelphia and his bad one with Tampa, Gudas ranked near the bottom in zone exit efficiency. Second, this is probably where Gudas earns his reputation as a poor puck handler. He's capable of contributing offensively with the puck on his stick, but when holding it in his own end, he often treats the puck like a hand grenade.

This also hints that his improvement in shot suppression has not come as a result of Gudas becoming better at moving the puck out of his own zone. He remains the below-average puck-mover that he has always been. That leaves his defensive play without the puck as a possible explanation for his improvement, specifically his ability to disrupt rushes in the neutral zone before they ever become dangerous.

And here we find our answer. Radko Gudas went from being a liability in defending rushes during the 2013-14 season with Tampa, to being competent at the same task with the Flyers.

Year Opponent Controlled Entry Percentage when targeting Gudas Opponent Controlled Entry Percentage when targeting team's other defensemen Percentage Differential 2015-16 (Philadelphia) 53.44% 51.88% -1.56% 2013-14 (Tampa Bay) 66.38% 59.72% -6.66%

Again, ignore the discrepancies in raw percentages. This is likely a result of tracker bias, as it's highly unlikely that the 2015-16 Flyers are that much better at preventing controlled entries than a solid 2013-14 Lightning team. Instead, pay attention to the differential. While Gudas is a little bit worse at forcing opponents to dump the puck into the zone relative to other Flyer defensemen, he was much worse back in 2013-14. In fact, among regular Tampa blueliners that season, only Matt Carle was worse than Gudas at preventing opponents from getting in on the attack with possession of the puck.

It seems like Gudas doesn't need to be a great neutral zone defender to be effective on the whole, considering his gifts with the puck on the attack. He just needs to be "not terrible" and he can make up for his weaknesses in getting the puck out of the defensive zone by helping his team to spend more time on the attack.

But why has Gudas taken such a leap in his ability to defend the rush? One theory is that he's simply become a better, smarter defenseman. After all, he was only in his age-23 season back in 2013-14 with the Lightning. Gudas is now right in the middle of his prime, and maybe his skillset has developed accordingly.

Another theory is that the Flyers' system under Dave Hakstol plays to his strengths. As we broke down earlier in the season, Philadelphia often employs an aggressive 2-1-2 forecheck that has two aims -- to generate more shot attempts in the offensive zone by putting heavy pressure on opposing defenders, and also to slow down transition rushes by making pinpoint passes in the defensive zone move difficult to execute.

Considering Gudas' willingness to help create offense by blasting away shots while on the attack, it's easy to see why the former goal fits the Czech defenseman's game perfectly. But the latter also helps him. Gudas is not a great skater, and can be exploited by fast forwards with a full head of steam in the neutral zone on rushes. Despite that, it's clear via the eye test that Gudas does have good instincts in the middle of the ice. He's fully capable of reading passes and cutting them off. He also can use his physicality to bottle things up along the boards or knock down an oncoming forward with a well-timed hip-check.

By slowing teams down in the middle of the ice, Hakstol's system allows Gudas to employ his strong disruption instincts without being victimized too often by speedy forwards coming right at him. Essentially, it minimizes the impact of one of Gudas' key weaknesses while letting him take full advantage of a major strength.

The result has been above-average shot suppression and a far more effective Radko Gudas.

Conclusion

The perception of Radko Gudas as a plodding, stay-at-home defenseman is not just incomplete, it's a totally inaccurate portrayal of his skillset. While his skating ability is not high-end and his play with the puck in the defensive zone has long been a weakness, Gudas actually is an above-average creator of offense from the back end. He moves the puck up ice like a Mark Streit or Michael Del Zotto, and takes shots at the rate of a Jake Muzzin or Erik Karlsson.

In fact, Gudas' deficiencies as a player lie more on the defensive side of the ice. In his second and third NHL seasons, the Czech blueliner both struggled to move the puck out of the defensive zone and to prevent opposing forwards from entering that zone with speed and possession. As a result, his on-ice metrics sagged, and he was eventually shipped to Philadelphia as a throw-in piece in last year's Braydon Coburn trade.

But Gudas' performance by the statistics has improved dramatically in his first season with the Flyers. His shot suppression ability has taken the biggest leap, as Philadelphia has done a better job of preventing opponents from firing pucks with Gudas on the ice versus when he is on the bench.

The reason? Gudas has become far better at disrupting rushes in the neutral zone. Whether it be a result of the Flyers' system better suiting his strengths and weaknesses, or that Gudas has simply fixed one of the previous issues of his game, the numbers are undeniable. Combine that with his ever-strong shot creation game, and Gudas has been one of the best possession defensemen in the NHL this season.

Radko Gudas may block a lot of shots and create a lot of hits. But don't pigeonhole him as yet another example of old-school thinking run amok. If he retains his improvement in the neutral zone from this season, Gudas' strong offensive instincts should allow him to thrive in the modern NHL for years to come.

All metrics from War-On-Ice.com, Corsica.Hockey, Stats.Hockeyanalysis.com, Corey Sznajder's All Three Zones project, or manually tracked by Charlie O'Connor.