Quote:
Originally Posted by GranteedEV
That's six goalies who've trended downwards the longer they've spent under Sigalet.
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One point I'd like to make: this looks like it was done with the average of the stats for the goaltender from game 1 until that point. Correct me if I'm wrong on that. If it is though, when I hear average with an increasing data set, I think that means that the data becomes more stable over time, no? One bad game (a ~30 shot sample size) will not ruin the mean save % as much as one bad game earlier in their career. For example if you start with a .900 save % and let in another shot, your save % gets much more affected letting in the 11th goal on your 101st shot against when compared to your 101th goal on your 1001st shot.
Such concerns can be seen in the first 15-20, which are so noisy they are near unreadable. Using a moving average should help reduce this type of bias in the data analysis but shouldn't destroy the loss of Save % if Flames goaltenders do have deteriorating save %s under Sigalet.
I tried something like this out myself to see if there is a correlation. Here were my conditions:
- I considered games where the goaltenders played a "significant" amount of the game (20 minutes or more) and only used regular season games. This removes effects such as playoff pressure and games with little data on goaltender (things do not meaningfully change if we removed games with <40 minutes)
- I manually calculated a 20 game moving save % after each game (9 before, 10 after...so all data starts at game 10). It would be calculated the expected way (1 - (# of goals against in 20 game period/# of shots against in 20 game period)).
- 10 game averages were also calculated, but were much noisier. The same conclusion should be reached either way.
- Players with more than 30 games played were plotted.
Here were the results.
The notable trends are in Johnson, Hiller, and Elliott.
- Johnson I would not explain well as he had a very short career.
- Hiller just flat out stopped caring at the end of his tenure here.
- Elliott had a really rough start and got better as time went on. The playoffs did see him struggle, but they were not included in this analysis.
With the others:
- Mike Smith seems too early to call. Is he a .91 save % goaltender who got hot for 20 games or is he a .93 save % goaltender who has had a couple slumps? There seems to be very little in between in his play. Maybe he would fit at .92 in this analysis and be streaky?
- Ramo seemed to be on a hot streak at the end.