Here's an update of an old post that I made:
Bourque was on the ice for 2,144 GA in 1,612 games.
Lidstrom was on the ice for 1,718 GA in 1,564 games.
However, when I compared their offense, I adjusted Bourque's stats because it was easier to score in his era. To be fair, we need to adjust Bourque's stats again because it was easier to be on the ice for a goal against. (If you disagree with this, you're basically asking me to adjust Bourque's offense down without making a corresponding adjustment to his defense - in other words, you're asking me to have a double standard to make Bourque's numbers look worse than they actually are).
The NHL averaged 6.86 goals per game during Bourque career, and 5.78 during Lidstrom's. (This is a simple average for each year - not weighted by the number of games they played - both were fairly healthy so if we do a games-weighted average, the results shouldn't be materially different - if someone wants to quantify this, go for it). The league was 18.7% higher scoring on average. Bourque was on the ice for 2,144 / 1.187 = 1,806 adjusted goals against.
Bourque was on the ice for 1,806 goals against in 1,612 games = 1.12
Lidstrom was on the ice for 1,560 GA in 1,412 games = 1.10
There you go. By this metric Lidstrom is about 2% better defensively that Bourque. He was on the ice for about 2% fewer goals per game, after taking into account the fact that Lidstrom played in a lower scoring era (which helps his defensive numbers).
Going into further detail, they're exactly the same in terms of even-strength goals against: both were on the ice for 0.76 GPG. In terms of non-ES goals (which would mostly be goals allowed while on the penalty kill, but also goals allowed while their teams are on the powerplay), Bourque was on the ice for 0.36 GPG, and Lidstrom 0.34 GPG.
This suggests they're close, but there are other factors to consider:
- This doesn`t differentiate between "shutting down opponents when they're already in the defensive zone" and "keeping the the puck out of the defensive zone altogether". Although the end results are similar, I suspect that Lidstrom was better at containing opponents once they're already in the team's zone, while Bourque was better at ensuring that the puck was at the other end of the rink. (This is a personal opinion though and I don`t have any data to support it).
- On average, Lidstrom played on better teams than Bourque. This would help him achieve better results, measured by goals against.
- Lidstrom missed the 2005 season due to the lockout. I'm not sure if that would help or hurt him in this analysis (since this is an "averaging" statistic rather than an "accumulation" statistic).
- This analysis looks at the data on a per-game basis. Like GAA for goalies, you really should look at goals against on a per-minute basis, rather than per-game. This adjustment would favour Bourque, since he played more minutes per game. We only have official ice-time data for the tail end of Bourque's career (ages 38 to 40), and he played between 26 and 29.5 minutes per game during that span. We have ice time data for most of Lidstrom`s prime (ages 28 through 37) - during which time he averaged 26.5 to 29.5 minutes per game. After his prime (ages 38 to 41), he avearged 23.5 to 25.5 minutes per game. We know that Bourque, at the tail end of his career, played significantrly more than Lidstrom did at the tail end of his career, and his ice time was actually quite comparable to Lidstrom's prime. Making the reasonable assumption that Bourque played more during his prime than from ages 38 to 40, this suggests that he received more average ice time over the course of his career and, for that reason, Bourque`s results are better than this analysis suggests (how much better is open for debate).
Based on the second and fourth points, I suspect that Bourque was probably a bit better than Lidstrom at keeping the puck out of their respective teams' nets. Even if the qualitative factors are ignored, they're virtually even.
