Reviewing Tomas Tatar's Stop in Vegas

Having watched the Canadiens many times over the past three weeks, I find myself thinking a lot about the two major trades involving Tomas Tatar (from Detroit to Vegas and from Vegas to Montreal). Since coming over from the desert (along with a second round pick and, at the time, prospect Nick Suzuki, who has looked extremely dynamic in his 134 5v5 minutes during the playoffs) in the deal that netted Vegas Max Pacioretty , Tatar has been sensational. He has scored 2.63 points per hour at 5v5 (1.6 is average for a forward) and found the back of the net 0.9 times per hour (where average for a forward is about 0.6). He has been a mainstay on the top line for Montreal with Brendan Gallagher and Phillip Danault and the team has controlled about 60 percent of the expected goal and shot share when he is on the ice. Given Montreal received additional compensation besides Tatar in the Pacioretty deal, it would be difficult to frame the deal as anything other than a slam-dunk for Montreal. Tatar is getting paid just 4.8 million against Montreal's cap through next season, while Pacioretty signed a seven million AAV extension through his age 35 season in Vegas. Despite his exploits with Mark Stone the past season and a half, this was a lopsided deal. 

This deal looks so great for Montreal with hindsight because Tatar was viewed as a distressed asset at the time of the trade. His brief stint with Vegas was a disaster. Vegas was getting caved in when Tatar was on the ice, to the point where he was scratched during the playoffs. Tatar only scored 0.92 points per hour at 5v5 and did not even record a primary assist. Prior to his move to the desert in 2018, Tatar was struggling in Detroit, where his scoring rate was cut in half from the previous season despite the team showing solid underlying performance when he was on the ice. Still, Vegas ponied up for him at the deadline, where they gave up a first, second, and third round picks. 

For some insight into how much he struggled during the 2017-2018 season, I scraped his individual rate stats from Natural Stat Trick starting in the 2015-2016 regular season and looked at his performance trends in two week samples. 

His ice time and shot attempt rates have been relatively consistent throughout the past five seasons, yet his scoring numbers have been a roller coaster.

In both cases there is a clear nadir in the 2017-2018 season. His goal scoring results were not even out of line with what should have been expected given the locations of his shots. His shot attempt rates were fine, but his expected goal rates took a big dip. He either was not receiving passes in dangerous scoring areas or his proficiency in carrying the puck to those areas just briefly deteriorated. 

The main indictment on Vegas in this ordeal is that despite Tatar's middling performance leading up to the trade deadline in 2018, they still had to put together a haul for Detroit to part ways with him. It was a lot to give up at the time for what many considered a very good second-line winger, but the principle of trying to acquire a player with middling scoring rates who was previously good while still showing good on-ice results is and was a sound one. But Vegas then flipped script and moved him for an older (albeit very good) player who needed a new contract and had to attach a draft pick and an elite prospect (who is looks like a top-six caliber player already). Maybe Tatar was just never going to fit in Vegas, but I am skeptical. This just seems like a misreading of the evidence we had on Tatar's ability and the variance of performance in hockey. 

As I mentioned above, Tatar scored just 0.92 points per hour at 5v5 with Vegas. Tatar played with Vegas for 6 weeks in the regular season. Given his scoring rates from the past four regular seasons, what are the odds that Tatar would put together a six week stretch as wretched as the one at the end of 2017-2018? I took all of his biweekly scoring rates and stored them in a table. I randomly sampled three (for six weeks of time) 10,000 times and plotted the distribution of rates in each six week sample:

This does not look good for Vegas. He exceeds his scoring rate in Vegas in 89.92 percent of the samples. Trading a guy after he put up points at a rate almost two standard deviations (when you include data from his time in Montreal) from his mean is just bad business. Luckily for Vegas Pacioretty has worked out fine. But as they look across the continent and see how Tatar and Suzuki (who is just 21 years-old) have performed for Le Bleu-Blanc-Rouge, part of them has to bemoan the fact that they committed the cardinal sin of selling a player who was just down on his luck.