Goaltending plays an integral part in the Stanley Cup Playoffs. NHL.com decided to break down a compelling matchup in the Western Conference Second Round, which starts Thursday when the Calgary Flames visit the Anaheim Ducks (10 p.m. ET; NBCSN, SN, TVA Sports): Jonas Hiller against Frederik Andersen, one of the young goaltenders who made Hiller expendable to the Ducks after last season.

Like many goaltending coaches will do before a playoff series, NHL.com correspondent Kevin Woodley, the managing editor of InGoal Magazine, charted every goal scored against each goalie in the regular season with the help of a program from Double Blue Sport Analytics. The graphics showing where goals went in and where shots were taken from on the ice are nice, but the real value is tracking and analyzing the types of plays that led to them and whether they reveal strengths, weaknesses and tendencies that can be targeted.

Jonas Hiller, Calgary Flames

OVERVIEW

Hiller never has apologized for playing from his knees. Nor should he have to, in part because he does it better than most and in part because his style is so often misunderstood. Hiller is more of a blocking goalie but that doesn't mean he isn't athletic or doesn't react. He just does it a little different, shifting his torso or shrugging his elbows and shoulders into shots rather than reaching for them.

Though the Ducks know Hiller's style well after he spent seven seasons in Anaheim, it has evolved in Calgary. Hiller is staying a little deeper in the crease playing behind the Flames' collapsing, shot-blocking philosophy, patiently holding his skate edges longer, even when it looks like he's already down, to buy time to react to late deflections off all those bodies in front of him.

Hiller also has diversified his post-integration options, reducing his exposure on plays from below the goal line and sharp angles.

When he's on: Hiller remains active and patient, holding his edges in that almost knock-kneed stance so he can shift his body into longer shots, and staying upright and balanced over his knees as he moves laterally in tight or slides side to side to beat passing plays.

When he's off: Hiller gets passive with his footwork and gets caught deep and flat on his posts. That poor positioning leaves him reaching, which spreads him out and has him off-balance on second chances.

GOAL TRENDS

Hiller's goal distribution is balanced in terms of left and right, with 40 goals beating him on the blocker side and 40 on the glove side. Ideally, we'd have a save percentage on each side to compare the differences, especially for a right-catching goalie who may see more glove-side shots as a result of shooters firing there instinctively because low blocker is their preferred spot. But there just isn't time to track every shot these goalies face in a season between playoff rounds. What we do see isn't a surprise: Other than the five-hole, which is explained in detail below, you aren't going to put many pucks through Hiller, especially glove side, because of how tight he holds it to his torso, using his body more than his hands to stop pucks.

Glove is on the wrong hand: That may sound silly to point out, but a couple Vancouver Canucks shooters admitted they fired into Hiller's glove side instinctually because low blocker normally is their go-to spot on quick plays; it took a couple of games in their first-round series for pre-scout reminders that Hiller catches with his right to become instinctual. That low-blocker instinct feeds perfectly into Hiller's lower glove position.

Got to get close for rebounds: Got to get close for rebounds: Even Hiller's equipment preferences are a perfect fit for the Flames' collapsing defensive system. Hiller likes his leg pads stuffed, without the stiffer foam core most of his peers prefer, because it allows him to feel shots off his legs and know where the rebound is headed. Most of the time the answer is "not too far." Hiller spilled plenty of loose pucks against Vancouver but almost always kept them close, in front of his tight, well-sealed butterfly, and behind the wall Calgary's defense puts up.

Narrow butterfly means five-hole opens: Hiller's blocking style tempts teams to try to beat him around the edges, but it's not always the best option on scrambles and in tight. Hiller has a narrow butterfly, meaning his skates are behind him when he drops rather than flared out wide to either side. So instead of closing his five-hole with the top of his pads like wide-butterfly goalies, Hiller squeezes his knees together to seal his five-hole. And because his pad coverage isn't as wide along the ice when he's on his knees, he's forced to move more on low shots, which opens his five-hole as he reaches with a leg, shuffles on his knees or lifts up a leg to push from side to side. Sixteen five-hole goals during the regular season is not alarming, but it's worth noting the Canucks scored four of 11 goals through Hiller's legs in their six-game first-round series.

Top corners off rush: This is where teams can target Hiller's default to the knees and tendency to drop his hands, especially once a play is below the hash marks. Despite being deeper on end-zone plays, Hiller does have a little backward flow on the rush and can get caught backing across the ice on passes from his right to left, a slight delay in his lateral movement caused by a momentum-build C-cut with the left skate that the Canucks exploited once in the first round. Of course the hard backchecking Flames aren’t going to give up a lot of those chances: 33 percent of goals allowed by Hiller during the regular season were against the rush, and three of 11 in the first round.

Low-high and elevate: Hiller plays pucks behind the net almost exclusively on his knees, but he does it so well you're unlikely to beat him with shots and walk-outs from dead angles. Low-high plays, or quick passes from behind the net, accounted for 12 percent of the goals he allowed during the regular season but led to three of 11 by the Canucks, in part because such plays can catch him deep and flat on the goal line, but also because it's tougher for the Flames' shot-blockers to adjust.

Frederik Andersen, Anaheim Ducks

OVERVIEW

It should come as no surprise that Andersen had success in the first round against the Winnipeg Jets despite playing two games in two weeks before the playoffs started. Andersen is a technically sound goaltender, smooth and efficient in his movements and positioning, leaving him less reliant on timing and rhythm and therefore less prone to lulls after time off. So the Flames can't count on any rust from a week of rest that followed Anaheim's sweep of Winnipeg.

When he's on: Andersen beats plays on his feet, establishing each new save position with a priority on angle first before adding depth, making sure he is set before the shot is taken.

When he's off: Andersen gets caught moving, sometimes with little lateral shuffles off the rush or with forward sculls to add depth on end-zone plays. When that happens, he doesn't get set and ends up reaching with his hands and trying to catch up to high shots with his head, opening holes.

GOAL TRENDS

There were two trends that jumped out as surprising when examining Andersen's regular season: The high number of clean shots that beat him (32, or 26 percent) and the 23 goals that went in under his pads or between his legs. The clean looks are explained below, but the five-hole goals are surprising for a goalie with a fairly wide natural butterfly flare, which allows him to close things up with the top of his pads while covering a lot of net low. Some five-hole exposure is explained by his tendency to set his feet wide and then reach for shots, rather than shifting into them, and that creates holes. He also turns his blocker sideways when defaulting into a butterfly block. That's fairly common, but he also pulls the stick blade away from the five-hole, adding exposure if he doesn't keep his pads sealed.

Far side off rush: Andersen isn't an overly aggressive goaltender in terms of his positioning, but he does have a little backward flow to his game against rush chances, and there were times this extra movement was exposed in the regular season. It can be seen in the 32 clean-look goals he gave up, many of which came on far-side shots from distance against the rush. It makes sense since Andersen, who gave up 37 percent of his goals against the rush, tends to track back on these attacks with small pushes laterally. So if, for example, he gets caught with his weight on his right skate while pushing left, it slightly delays a reaction back to his right.

Elevate in a scramble: Unlike Hiller, who can be more vulnerable along the ice during scramble situations in tight, it's important to get rebound opportunities at least one foot off the ice against Anderson. He'll pitch forward with his torso in desperation situations to buy himself some extra leg extension, making sure to take away the bottom 11 inches of the net on both sides with his pads.

One-timers off end-zone lateral passes: Much like rush chances, Andersen tends to take a little more ice on end-zone play than some think is necessary for a 6-foot-3 goalie, getting just outside the edges of his crease. Though he's usually quick enough with his feet to recover that space on lateral passes, the extra distance can be costly on one-timers after cross-ice feeds (26 percent of his goals against this season), either with shots that beat him just inside the post on the side he's moving to, or with less controlled rebounds (24 percent of his goals against) because he's still moving as he makes the initial save.

Rebounds off sharp-angled blocker side and far pad: Andersen allowed 24 percent of his goals on rebounds in the regular season, and there were a couple trends the Flames may try to exploit. The first is sharp-angled shots on his blocker side, which often ended up steered into the slot, led to several goals against in the regular season and forced Andersen to make a couple big saves against the Jets. The other is throwing pucks off the far pad for rebounds on the other side. That's a common plan for any goalie, but with a less active stick to steer those shots into a corner, Andersen leaves more of them in the high slot on the other side, and that led to goals during the regular season and several tough saves so far in the playoffs.