Blog 6: Player evaluation – The Goaltenders

Next up is the goaltenders – the Achilles Heel of every hockey statistician. There are generally two ways to judge goalies. You either go with goals saved above average (GSAA) or you go with goals saved above expected (GSAx) which is based on xGA. GSAA relies solely on the number of shots against and the number of goals allowed. GSAx is the difference between expected goals against and actual goals against, so it depends on the number of shots and the quality of the shots. The problem is that xG-models aren’t perfect when it comes to evaluating goaltending.

My model is basically GSAx with some slight adjustments. Here’s the top 20 goalies since season 2007/2008:

PlayerGPSv%GSAAGSAxLS-GAA_GK
Henrik Lundqvist76491.78127.98268.46284.65
Jaroslav Halak50491.6864.0995.93105.57
John Gibson28791.8353.3081.2986.68
Carey Price68291.74111.2758.5583.76
Jonathan Quick64491.3418.4953.0867.82
Roberto Luongo62691.83109.5547.6266.97
Sergei Bobrovsky50791.7166.5758.1266.55
Braden Holtby46891.6044.3556.1162.40
Jonas Hiller40491.4421.5952.6161.87
Corey Crawford48691.7868.3856.2960.34
Cory Schneider40991.8054.8758.1758.13
Frederik Andersen36991.6546.0649.7756.62
Cam Ward61191.03-30.5635.1255.06
Cam Talbot31491.5120.6749.3949.43
Tomas Vokoun31692.16104.6826.3948.07
Ben Bishop41392.0588.4041.9548.04
Evgeni Nabokov34491.175.2426.1446.60
Antti Raanta18692.0641.6043.5746.11
Tim Thomas31792.36114.6627.3544.15
Tuukka Rask53692.18134.8836.4743.21

I already discussed Lundqvist back in blog 3. While he’s obviously a great goalie, he still seems a bit overrated when it comes to GSAx/LS-GAA. New York Rangers historically has a bad xG against, which theoretically makes it “easier” for Lundqvist to have a good GSAx. Most of this is obviously due to the team play of the Rangers, but part of it could also be due to rebound control. If the goalie gives up a lot of rebounds it naturally leads to a bigger xGA, and perhaps a better GSAx. So even though bad rebound control isn’t a good goalie trait, it could actually be a good thing for your GSAx. This could be part of the explanation regarding Lundqvist.

Here’s the best goalies in terms of GSAA. Lundqvist is still great, but now he’s human.

PlayerGPSv%GSAAGSAxLS-GAA_GK
Tuukka Rask53692.18134.8836.4743.21
Henrik Lundqvist76491.78127.98268.46284.65
Tim Thomas31792.36114.6627.3544.15
Carey Price68291.74111.2758.5583.76
Roberto Luongo62691.83109.5547.6266.97
Tomas Vokoun31692.16104.6826.3948.07
Pekka Rinne65791.7391.28-16.58-0.23
Ben Bishop41392.0588.4041.9548.04
Ryan Miller65091.6280.1513.4237.35
Corey Crawford48691.7868.3856.2960.34
Sergei Bobrovsky50791.7166.5758.1266.55
Jaroslav Halak50491.6864.0995.93105.57
Robin Lehner30191.8557.16-9.80-2.21
Andrei Vasilevskiy26091.9057.04-32.39-21.68
Marc-Andre Fleury70891.4956.5610.2734.54
Cory Schneider40991.8054.8758.1758.13
John Gibson28791.8353.3081.2986.68
Frederik Andersen36991.6546.0649.7756.62
Connor Hellebuyck26991.7145.6427.7737.41
Braden Holtby46891.6044.3556.1162.40

So what list ranks the goaltending best? The truth probably lies somewhere in between GSAA and GSAx. I honestly don’t think there’s any good way to measure goaltending as of right now. It’s almost impossible to distinguish between good goaltending and good team defense. The new upcoming tracking data may lead to a better goalie stat. Until then, this is what we got.

Here’s the players with the biggest positive difference between LS-GAA and GSAA. The worst teams in terms xGA per 60 minutes are: Edmonton, Islanders, Rangers and Carolina. Those are also the teams dominating this list.

PlayerSeasonTeamGPSv%GSAALS-GAADiff
Henrik Lundqvist09-10NYR7392.0820.1751.5231.35
Henrik Lundqvist08-09NYR7091.6315.6946.3030.61
Henrik Lundqvist07-08NYR7291.195.2828.2322.95
Jaroslav Halak14-15NYI5991.39-1.1818.1719.35
Ondrej Pavelec13-14WPG5790.09-21.45-4.1817.27
Nikolai Khabibulin10-11EDM4788.98-31.93-14.8717.06
Cam Ward09-10CAR4691.474.6821.4416.76
Kari Lehtonen16-17DAL5990.24-17.17-0.9816.19
John Gibson18-19ANA5891.6812.8329.0016.17
Kari Lehtonen13-14DAL6591.99.5525.0015.45
Devan Dubnyk11-12EDM4791.451.3315.5514.22
Cam Talbot16-17EDM7391.9312.3126.4214.11
Ondrej Pavelec11-12WPG6890.62-14.94-0.9713.97
Cam Ward07-08CAR6990.37-9.903.9113.81
Dwayne Roloson09-10NYI5090.65-7.446.1413.58
Evgeni Nabokov13-14NYI4090.51-9.583.6913.27
Henrik Lundqvist11-12NYR6292.9828.5941.0912.50
Cam Ward11-12CAR6891.513.3115.7612.45
Ondrej Pavelec14-15WPG5092.027.5019.6712.17
Nikolai Khabibulin11-12EDM4091.02-3.678.4812.15

We can also look at the other end of the spectrum. Here’s the goalies with the biggest negative difference between LS-GAA and GSAA. The teams with the lowest xGA per 60 are: Minnesota, Boston, New Jersey, St. Louis and Nashville.

PlayerSeasonTeamGPSv%GSAALS-GAADiff
Devan Dubnyk16-17MIN6592.3518.35-9.86-28.21
Andrei Vasilevskiy17-18T.B6591.9515.09-12.00-27.09
Niklas Backstrom08-09MIN7192.2829.453.60-25.85
Robin Lehner16-17BUF5992.0513.41-9.60-23.01
Devan Dubnyk17-18MIN6091.810.23-11.80-22.03
Niklas Backstrom07-08MIN5791.8114.54-6.05-20.59
Devan Dubnyk18-19MIN6791.326.17-13.30-19.47
Tim Thomas11-12BOS5992.0411.46-7.80-19.26
Tuukka Rask13-14BOS5892.9926.297.07-19.22
Jimmy Howard09-10DET6392.3723.104.18-18.92
Niklas Backstrom09-10MIN6090.33-12.96-31.50-18.54
Tuukka Rask14-15BOS7092.2415.67-1.45-17.12
Andrei Vasilevskiy16-17T.B5091.695.03-11.67-16.70
Pekka Rinne11-12NSH7392.2920.183.99-16.19
Pekka Rinne14-15NSH6492.2514.26-1.93-16.19
Sergei Bobrovsky13-14CBJ5892.2915.28-0.78-16.06
Roberto Luongo14-15FLA6192.0810.79-4.56-15.35
Steve Mason11-12CBJ4689.45-25.83-40.66-14.83
Tim Thomas10-11BOS5793.8245.8531.17-14.68
Ben Bishop15-16T.B6192.6519.475.04-14.43

My point is some goalies are likely overvalued if you judge them by LS-GAA or GSAx, while others are undervalued. I don’t think GSAA is any better though, so perhaps the smartest way to evaluate goalies is by combining the two. That’s something for another blog. Let’s instead turn our attention to this season.

Season 19/20:

PlayerGPSv%GSAALS-GAA
Connor Hellebuyck5892.2022.3526.18
Darcy Kuemper2992.8016.6311.79
Tuukka Rask4192.8522.4811.60
Corey Crawford4091.669.0610.84
Mikko Koskinen3891.749.1310.06
James Reimer2591.433.369.70
Jake Allen2492.6711.219.39
Antti Raanta3392.1111.669.19
Ben Bishop4491.9913.258.93
Carter Hart4391.364.448.76
Anton Khudobin3092.9717.738.70
Chris Driedger1293.7910.008.40
Jordan Binnington5091.203.458.26
Robin Lehner3691.9812.647.76
Jacob Markstrom4391.7611.367.75
Igor Shesterkin1293.169.337.44
Calvin Petersen892.193.327.28
Pavel Francouz3492.2512.856.62
Henrik Lundqvist3090.50-4.096.56
Alexandar Georgiev3490.970.096.55

Hellebuyck has been pretty great this season, especially when looking at LS-GAA. If you look at Sv% he has still been good, but not quite as good. It’s also worth noting that a true starter like Hellbuyck is rare these days. Most teams go with an 1A/1B situation and that strategy seems to be working for a lot of teams.

I have also listed best goalies measured by GSAA:

PlayerGPSv%GSAALS-GAA
Tuukka Rask4192.8522.4811.60
Connor Hellebuyck5892.2022.3526.18
Anton Khudobin3092.9717.738.70
Darcy Kuemper2992.8016.6311.79
Ben Bishop4491.9913.258.93
Pavel Francouz3492.2512.856.62
Robin Lehner3691.9812.647.76
Andrei Vasilevskiy5291.7112.09-1.53
Elvis Merzlikins3292.2712.072.81
Antti Raanta3392.1111.669.19
Jacob Markstrom4391.7611.367.75
Jake Allen2492.6711.219.39
Tristan Jarry3392.0610.774.38
Chris Driedger1293.7910.008.40
Igor Shesterkin1293.169.337.44
Mikko Koskinen3891.749.1310.06
Corey Crawford4091.669.0610.84
Jaroslav Halak3191.938.816.18
Cam Talbot2691.927.513.07
Mackenzie Blackwood4791.467.264.68

That’s it for now. Goaltending is very difficult to measure, and LS-GAA is in no way perfect. It does however fit with the other LS-GAA components, so that the overall result is right. In other words, LS-GAA_Total describes team results really good, but that doesn’t necessarily mean that the goaltending component tells the truth.

Next time I will divide players into tiers using LS-GAA per 60, and use these tiers to discuss how to best construct a team.

Conclusion:

  • Goaltending can’t be effectively measured – that’s my belief.
  • Goaltending is more or less unpredictable with the current metrics, but at the same time goaltending is hugely important. So if you can somehow predict future goaltender performance, then you can make a great projection model.

Stay safe and remember to be kind

All raw data from evolving-hockey.com

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