2022–23 NHL goals saved above expected comparisons across the league: Week 12

The NHL rung in the new year with games aplenty as the season is rapidly approaching its midpoint. The Los Angeles Kings are the first team to reach that mark, having played 41 games now. The goaltending picture in the league continues to see trends with stable goalies outperforming their counterparts, as well as some new faces picking up momentum in the crease. Let’s see how the week in GSAx has looked.

Goals saved above expected as of January 3, 2023

If you’ve seen these plots before, please feel free to scroll right down and start checking out the visualisations. Otherwise, here’s a quick explainer on how to read the GSAx charts.

One way to objectively compare goaltenders is to evaluate their goals saved above expected (GSAx). For every shot, there’s an assigned expected goal (xG) value, and as a goaltender makes or doesn’t make saves based on expected values, the difference between their xG against and their actual goals against will start varying compared to other goaltenders.

With the randomness of goaltending seemingly happening not just season over season but at times even week over week, we can plot every goaltender’s GSAx to see how they stack up compared to the rest of the league. Using data visualisation, comparing goaltenders can be done quickly with a lot of context in each chart.

Each set of charts will be weekly from Wednesday’s games through to the following Tuesday’s games. This is to capture the additional slate of games typically played on Tuesdays, for no other reason than to have the most data available in a timely, yet weekly manner.

In addition to weekly GSAx plots, season-to-date charts will also be looked at to see how goalies stack up against one another over the course of a season. This will help highlight which goaltenders are among the best and who should be frontrunners for the Vezina Trophy. All data is from NaturalStatTrick.com.

Weekly goals saved above expected plots

The plots are split into each division, and then teams are ranked in order of the highest total team GSAx to the lowest. Each goaltender will then sit along the x-axis based on their GSAx totals. The colour of each goaltender is determined based on total shots against compared to the whole league (as opposed to per division)—the more shots a goaltender faces, the brighter and yellower their point; the fewer shots, the darker and bluer.

Similarly to the shots against colour being league-wide, the x-axis per plot is also scaled league-wide, based on the two individual goaltenders with the highest and lowest GSAx. This makes visual comparisons between the four plots a bit easier.

Pacific Division goaltenders

The plots this week go from -10.0 to 5.0 GSAx. This means that somewhere in the league, at least one goaltender ended up with under -5.0 GSAx while no goalies ended up higher than 5.0 GSAx. Looking at the Pacific, most teams had mixed results. The top four teams all had one goalie above zero and one below—all to various degrees. Because of that, the top team was the Vegas Golden Knights, who was led by Logan Thompson.

Of the four bottom teams, only the Edmonton Oilers had a positive GSAx performance from Jack Campbell, but it was too close to breakeven to pull the Oilers up any higher.

One interesting performance came from Pheonix Copley, who is boasting a seven-game win streak despite being negative in GSAx this week. That said, he was close enough to breakeven and got wins on the board despite ceding four and then two goals in his appearances over the past seven days.

Central Division goaltenders

The Central Division has a wide spread in GSAx, and it’s actually Alexandar Georgiev with the GSAx lower than -5.0. He’s the only goalie in the NHL to be below that mark this week.

Connor Hellebuyck led the division this week as he often does. He rarely goes more than a week not being at the top of the Central. The second and third place teams in the division also used just one goalie each as Jake Oettinger and Marc-Andre Fleury both performed well in GSAx as well.

One of the busier goalies was Karel Vejmelka, and while he’s put together a strong run on GSAx this season, this past week saw him struggle.

Metropolitan Division goaltenders

For the first time, the Columbus Blue Jackets had the best GSAx in the Metropolitan and it was thanks to Joonas Korpisalo. This team has mightily struggled with GSAx this year so this is a big surprise outcome.

With Carter Hart out due to concussion protocol, Samuel Ersson went and had himself a spectacular week. He won three games and was near the top in GSAx among all goaltenders this week.

Overall it was a fairly solid week for the Metro. Only Pyotr Kochetkov and Darcy Kuemper seemed to struggle a bit, and even then it wasn’t by a significant amount and both of these goalies are usually positive GSAx goalies.

Atlantic Division goaltenders

The Atlantic Division saw a whole bunch of disparity within teams and across teams. The Tampa Bay Lightning led with Andrei Vasilevskiy’s performance, but even then he was only the third best goalie in the Atlantic this week. Linus Ullmark and Anton Forsberg both had better GSAx, but unfortunately their counterparts Jeremy Swayman and Cam Talbot, respectively, had negative GSAx that was too much to overcome to challenge for the top spot.

Brian Elliott on the other hand, had a decent enough week as to not anchor down Vasilevskiy. Alongside Tampa Bay, the only other team with all positive GSAx were the Buffalo Sabres, although both Ukko-Pekka Luukkonen and Craig Anderson had marginally positive values.

The bottom three teams in the Atlantic saw all of their goalies net negative on GSAx. This includes Montreal, Florida, and Toronto.

Season-to-date goals saved above expected plots

Now turning to season-to-date plots, let’s check out how the season stacks up. The colour palette for the season-to-date charts is also changed to differentiate them from the weeklies.

The plots are rescaled to account for different maximum and minimum GSAx values, but as above, all four divisions are scaled together to make the season-to-date comparisons easier. The scale remains from -20.0 to 25.0 GSAx, with a few goalies at the top while many more are straddling the bottom.