Sunday Hockey Notes

Checklight device mines data on head shots

Former Bruins forward Marc Savard.
Yoon S. Byun/Globe Staff
Former Bruins forward Marc Savard.

Marc Savard suffered his final hit as an NHL player Jan. 22, 2011. The blow from teammate Matt Hunwick happened less than 10 months after Matt Cooke delivered his blindside wallop.

The hit that is less obvious but might have contributed to Savard’s condition happened Jan. 15, 2011.

Pittsburgh’s Deryk Engelland closed on Savard as he passed the puck. The force of Engelland’s approach drove the back of Savard’s head into the TD Garden boards. Savard went down, but he played in the next four games, the last of his career.


It’s possible the Reebok Checklight could have red-flagged Savard’s condition following Engelland’s check.

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The Checklight, developed in conjunction with Cambridge-based electronics company MC10, is a wearable device that monitors head impacts.

A hockey player would wear a skull cap under his or her helmet. A tab containing impact sensors slides into a groove inside the cap. An indicator with green, yellow, and red lights is positioned outside the cap along the back of the player’s neck.

Green means all is well. The light turns yellow when sensors recognize an athlete absorbs a moderate impact. Red indicates a severe impact. The degrees of severity are based on Head Injury Criterion (HIC). The US National Highway Traffic Safety Administration uses HIC values to determine car safety ratings.

The Checklight does not diagnose concussions. A red light does not indicate a player has suffered a severe concussion. Rather, the Checklight is meant to be a guidepost in a field absent of clarity.


A concussion’s consequences are well known. Headaches, nausea, memory loss, dizziness, and sensitivity to light are common symptoms.

The cause of a concussion and its symptoms are cloudy. There are variables, such as an athlete’s injury history, the force of hit sustained, or how the hit’s energy dissipated.

Reebok designed the Checklight (available at Dick’s Sporting Goods and for $149) to provide black-and-white feedback — green, yellow, and red in this case — when a troubling blow takes place. The Checklight’s accelerometer tracks linear impacts. Its gyroscope monitors rotational impacts.

“We’re trying to give the athlete, coach, parent, athletic trainer, teammates an idea that you have sustained a moderate or severe impact, so just get it checked out,” said Paul Litchfield, Reebok’s vice president of advanced concepts. “More often than not, the notion of, ‘Just suck it up, it’s OK,’ plays well for the tough-guy image. But ultimately, if you’ve sustained a force and you’re not doing well, you should probably get it checked out.”

Litchfield is the creator of the Pump, Reebok’s iconic basketball sneaker. He and his team work in a skunkworks-type facility next to Reebok’s corporate headquarters in Canton.


Over the last 2½ years, Litchfield led the Checklight through multiple levels of design and testing. In one room of the facility, the head from a crashtest dummy is attached to a mechanism that propels it toward a block, which can be fitted with multiple surfaces: ice, wood, grass. The mechanism launches the head, which contains an accelerometer, at different speeds and angles. The variable tests helped designate differences between moderate and severe impacts.

The Checklight also went through on-ice testing. The Buckingham, Browne & and Nichols JV hockey team was recruited to participate.

During one test, a youth player tumbled headfirst into the post. The net was dislodged. The boy said he was OK. The Checklight flashed yellow. Coaches and trainers assessed the player and declared him fit to continue. But the scenario is one that Litchfield hopes will prove the Checklight’s worth.

In the NHL, thousands of eyes see a high-impact hit: players, coaches, referees, trainers, fans, TV watchers. Some of those observers can help convince a woozy player to head to the dressing room.

That’s not the same in youth hockey. The coach might be looking the other way. Parents are watching their own children. The referee is following the puck, not the collision that took place on the other side of the rink. When a player who took a heavy hit returns to the bench bearing a yellow or red light, a coach can recognize he or she might not be fit for the next shift before being examined.

The Checklight is geared toward the mass market. Its target is not pro hockey players. The NHL has not approved the Checklight for in-game use. Reebok declined to disclose the Checklight’s sales numbers.

After the Engelland hit, Savard was not diagnosed with a concussion. Doctors cleared him for play. Savard felt ready to dress two nights later against Carolina.

However, based on the severity of Engelland’s hit, the Checklight might have flashed yellow or red. In such situations, it is up to the user and his periphery (coaches, trainers, parents) to determine the next step — play on, sit out a shift, call it quits for the rest of the game.

One player might shake off a red-level hit if he feels fine. Another player might sit out the rest of the period after a yellow-level impact. There is no guidebook to follow because concussion knowledge remains in its nascency.

Players at all levels skate through red-level wallops without harm. But a casual swipe that might not even trigger the Checklight’s yellow light — consider Colin Greening’s glancing bump last season that resulted in Patrice Bergeron’s fourth career concussion — could spell trouble for other players.

Litchfield acknowledges the gray areas surrounding concussions. The Checklight is not a panacea. But it could be a first-generation product — subsequent versions are in development — to give athletes tangible feedback in a still-murky field.

“It’s not meant to be diagnostic,” Litchfield said. “It’s not meant to be onerous. It’s just meant to be informative. This is not meant to alter people’s play: ‘Oh, you shouldn’t play hockey.’ If you twist your knee, you’ll get it checked out. If you cut your eye, you’ll get it butterflied and get back at it. If you have gotten an impact to your head, how much? What was it? This is just meant to give you an indication.”


Statistics not as they appear

In 2013, Alex Tanguay landed 44 shots on goal. Eleven went in. Tanguay’s shooting percentage of 25 was not out of character. Entering this season, Tanguay has an 18.8 career shooting percentage.

At the other end, Tuukka Rask posted a .929 save percentage last season. Similarly, Rask’s 2013 performance was not an outlier. Rask’s career save percentage is .927.

The shortcoming of both statistics, however, is their inability to reflect the degrees of shots and saves. Tanguay’s shooting percentage doesn’t measure where he was when he buried those shots; statistics show that head-on shots, compared to those from angles, are more likely to go in. Rask’s save percentage doesn’t say how many saves were of tipped pucks, which are far tougher to stop than a no-traffic wrister from the right point.

On Sept. 21, as part of the New England Symposium on Statistics in Sports, presenters Calla Glavin, Brian Macdonald, and Nicholas Clark submitted their work on applying advanced statistics toward shooting and save percentages.

Their abstract, Estimating Goal Probabilities in the NHL, studied how introducing coefficients regarding predictors — shot location, time of game, and type of shot (wrist, slap, tip), for example — amplifies percentages that those within the league regularly cite in evaluation.

The model is based on hierarchical Bayesian techniques, a term Glavin uses with a forgiving smile to a confused scribbler. In basic terms, the model adjusts shooting and save percentages to include the game’s variables. As a result, Ilya Kovalchuk’s adjusted shooting percentage is better than Tanguay’s over a three-season sample. Roberto Luongo’s adjusted save percentage is higher than Rask’s.

Anecdotally, Alex Ovechkin is considered one of the NHL’s most dangerous shooters. But Ovechkin does not appear on the presenters’ top-10 list, partly because of the high number of low-percentage shots he takes.

“There are so many different things going on — distance, angles, rebounds, changing,” Glavin said. “If you took into account all of those measures, these patterns still emerge. It confirms what coaches and players already see on the ice a lot of the time. But there are things that people don’t expect, like Ovechkin not being on this list — not being in the top 10, not even being in the top 20.”


Enforcer Scott not worth it

For anyone questioning why John Scott receives $750,000 annually, consider the aftermath of last Sunday’s dustup with the Maple Leafs. David Clarkson: out for 10 regular-season games. Phil Kessel: done for the preseason. Rest of Toronto organization: foaming for revenge on Nov. 15, when the Leafs visit the Sabres. Toronto and Buffalo should be fighting for one of the two wild-card bids in the Eastern Conference. Now, with Clarkson ineligible to play until Oct. 25, the Leafs might be looking up at the rest of the Atlantic Division when the rematch takes place. When Scott dropped the mitts and chased after Kessel, nothing would have happened had the Leafs pig-piled atop the monster. No linesmen would have allowed Scott to start chucking. When they play again, the Leafs should do the wise thing and instruct Colton Orr and Frazer McLaren to ignore Scott. There’s no reason to engage a one-dimensional player who submitted the following stat line last season: 34 games, 0-0—0, 5:26 average ice time. As for Kessel, the ex-Bruin received more of a reward than punishment. Nobody can blame Kessel for reacting like he did when Scott started his charge. In fact, Kessel should have asked the equipment manager for an upgrade over his whippy stick. The preferred piece might have been a samurai sword like the one Bruce Willis chose in “Pulp Fiction.” Scott would have laughed off both the hammer and baseball bat.

Next in line on defense

With offensive defenseman Mark Streit now in Philadelphia, the Islanders will most likely turn to youngster Matt Donovan to replace their former captain’s back-end output. The left-shot Donovan scored 14 goals and 34 assists last season for Bridgeport in the AHL. The Islanders took Donovan in the fourth round in 2008, one pick after St. Louis drafted current Bruins blue-line prospect David Warsofsky, also an offensive-minded defenseman. Donovan, teammates with ex-Bruin Joe Colborne at the University of Denver, played two years of college hockey before turning pro in 2011.

Younger Donato emerging

Ryan Donato, son of ex-Bruin and current Harvard coach Ted Donato, recorded two assists in USA Hockey’s All-American Prospects Game in Pittsburgh on Thursday. The 17-year-old Donato is a left-shot forward who plays for uncle Dan Donato at Dexter. On Monday, the NHL’s Central Scouting Service included Ryan Donato in its preliminary rankings for the 2014 draft. The CSS rankings tabbed Donato as a B-level skater, which means he could be a second- or third-round pick.

They’ve earned their stripes

Five referees will make their NHL debuts in 2013-14: Tom Chmielewski, Trevor Hanson, Dave Lewis, Thomas John Luxmore, and Jon McIsaac. In comparison, longtime zebra Paul Devorski enters the season with 1,450 games on his résumé. In all likelihood, that’s more than 50,000 career insults for the 55-year-old Devorski. And that’s just from coaches.

Wings have Swede pipeline

The Red Wings are expecting big things from former University of Maine forward Gustav Nyquist this season. Nyquist, the 121st overall pick in the 2008 draft, split time between Detroit and Grand Rapids last season. Nyquist should be ready for a full-time NHL job. He was a point-per-game player in 2012-13, scoring 23 goals and 37 assists in 58 appearances. General manager Ken Holland describes Nyquist as another of the organization’s skilled Swedish players (he joins Henrik Zetterberg, Johan Franzen, Daniel Alfredsson, Joakim Andersson, Niklas Kronwall, and Jonathan Ericsson) with plenty of hockey sense. On-ice intelligence is one of the primary characteristics the Red Wings seek in their players, not just the ones hailing from Sweden.

Bartkowski confident

The part of Bruin Matt Bartkowski’s growing confidence that’s catching eyes is his poise with the puck. Bartkowski has been especially comfortable skating the puck out of his zone when passing lanes aren’t available. Bartkowski has been quick to serve as a one-man breakout since he contributed in last year’s postseason. “He beat two forecheckers by himself,” said one Eastern Conference scout after the Bruins’ 3-2 preseason win over Washington on Monday. If the Bruins can’t re-sign Dennis Seidenberg, Bartkowski could be the stay-at-homer’s replacement on the second pairing. Both Seidenberg and Bartkowski arrived on March 3, 2010, when GM Peter Chiarelli fleeced Randy Sexton of the Lightning. The Bruins parted with Byron Bitz, Craig Weller, and a 2010 second-rounder, which they had acquired from Tampa Bay in the Mark Recchi trade, another of Chiarelli’s stickup jobs.

Loose pucks

Josh Bailey’s best NHL season was in 2009-10, when the former first-round pick scored 16 goals and 19 assists in 73 games for the Islanders. Bailey should improve on those numbers if he can retain his spot on the first line alongside Matt Moulson and John Tavares. Bailey is filling the right-wing job formerly assumed by ex-Bruin Brad Boyes, who scored 10 goals and 25 assists while riding shotgun with Moulson and Tavares . . . New Jersey will have 22 back-to-back games, most in the league. If the goalie tandem of Martin Brodeur and Cory Schneider holds strong, the Devils should be able to survive the two-in-two grind . . . NHL Center Ice will be available for free from Tuesday through Oct. 10. The season package is $159.96 if ordered before Oct. 31 . . . Daniel Paille will host a dinner Oct. 7 to benefit the Dana-Farber Cancer Institute and the Jimmy Fund. The dinner will be at Tresca and will include a meeting with Paille, silent auction, and beer tasting. Tickets are $50. For tickets or more information, visit . . . The Bruins will have a league-high 17 home games in the first two months, including 10 in November. They have to take advantage of the light early schedule to stack up points. In contrast, Dallas and the Rangers have only 10 home games in October and November combined. The Stars and Rangers could be out of it early if they stumble . . . The Bruins will leave on Sunday for team-building activities in Vermont. In 2008, the Bruins also visited the Stowe/Waterbury area for practices and team building. As part of the visit, they held an autograph signing at Ben & Jerry’s, where old friend Aaron Ward obliterated the factory’s creamiest offerings. Vermont’s dairy industry has yet to recover.

Fluto Shinzawa can be reached at Follow him on Twitter @GlobeFluto. Material from interviews, wire services, other beat writers, and league and team sources was used in this report.