His stats will not necessarily improve by a huge amount. Depending on the value place in different stats it could be considered that his stats declined given an improved D and the same level of play from Dubnyk. His GAA in 2012-13 was an atrocious 23rd overall. He was a decent 12th in SV PCT. If the Oilers defence improves it is reasonable to expect his GAA to improve to 20th. The save percentage may actually decline.
The save percentage is a quirky stat. Hard to replicate and based on some minor differences. An improved defence could lead to his facing fewer shots. Say an improved defence clears the odd puck that last year's team couldn't. If they clear one extra puck a week over the season that prevent shots, Dubnyk's save percentage drops one point to .919 and from 12th overall to 14th.
That is for one fewer shot 20 times in a 48 game season.
The consensus is the 2013-14 D corps is improved. What if they cut down on just one shot a night. Dubnyk's level of play is the same, so most of those goals go in. Save for a smaller number due to improved defensive play. How about 7 fewer goals. One a month is a reasonable guess. That improves his GAA to 2.47 from 23rd to 20th.
With the improved D his stats show slight improvement. If he can cut down on mental errors he has a chance to make a quantum leap. This year it is completely up to him. He is playing in front of the best defensive corps he has ever had in front of him.
All of my projections are reasonable outcomes if Dubnyk doesn't improve his play, or fall off, significantly. If he doesn't make the jump this year it's time for everyone to move on.
Dubnyk's personal performance is up to him, I agree: better focus, better angles, etc., these are all aspects that Dubnyk has 100% control over, and if he can improve on these aspects of his game himself and the Oiler's will both benefit.
IMO, improved defense is not necessarily reflected in the number of shots a goaltender faces in a game or over the course of a season; improved defense is reflected in the quality of the shots faced during a game or over the course of the season. A goaltender facing 35 shots from the red line will more than likely have better stats than a goalie facing 25 shots from the slot. Unfortunately, there is no reliable way to predict the affect an improved defense has over the quality of shots faced per game, thus no real predictive measure that can be used to determine the affect this has on a goaltenders stats (if there is a way that I am unaware of, please feel free to point me in the right direction).
How are you calculating Dubnyk's save percentage in your example? Are you adjusting shots against and GA's based on fewer shots on some sort of factor, or are you assuming every shot prevented would have been a save had it not been prevented? Lets see:
Shots Faced (Less 20): 1112
GA (unadjusted): 90
Saves Made: 1112-90 = 1022
Projected Save percentage: 1022/1112 = .919
Seems as if you used the latter assumption. It does not seem reasonable to punish Dubnyk for facing less shots during a season. While a .919 save percentage could qualify as reasonable, using subjectively altered stats to express your view only weakens its position, not furthers it. Case in point (very extreme example):
Shots Faced (Less 20): 1112
GA (Less 20): 70
Saves Made: 1112-70 = 1042
Projected Save percentage: 1042/1112 = .937
With the assumption all 20 shots prevented would have been goals otherwise, Dubnyk's save percentage is now 2nd best in the league (I'm guessing his GAA is also pretty high up there as well). Seems unreasonable doesn't it? A possible reasonable approach might be to use Dubnyk's current save percentage against the decreased shots; therefore, on 20 shots Dubnyk would have made 18 saves and allowed 2 goals. The analysis would look like this:
Shots Faced (Less 20): 1112
GA (Less 2): 88
Saves Made: 1112-88 = 1024
Projected Save percentage: 1024/1112 = .921
This results in a slight improvement, and does not take into account the quality of the remaining 1112 shots. For presentation sake, lets combine this with your GAA analysis of 7 fewer goals over the course of the season (the additional 5 we could say being attributed to the quality of shot factor):
Shots Faced (Less 20): 1112
GA (Less 7): 83
Saves Made: 1112-83 = 1029
Projected Save percentage: 1029/1112 = .925
This save percentage would be 7th overall in the league. the GAA of 2.47 moves Dubnyk from 26 to 23, but if we remove backup goaltenders (I'm suggesting 5: Bernier, Emry, Khudobin, Allen, Vokoun), that puts Dubnyk at 18th overall for starting goaltenders (the merits behind including or not including backup goaltenders, and which goaltenders are backup goaltenders is up for debate). I would argue that an improved defense, and consistent play from Dubnyk, improves his stats (at least league rank wise) considerably. Would that not be worth $4.75 on a long term contract? I think it would be. If the defense is improved, and Dubnyk improves the areas of his game that are 100% under his control by even 5%, I would be willing to argue that the above increase in stats would be the minimum increase we would see on the season.
Everything above not withstanding, if there is a decrease in his play and his statistics, then I agree fully that the Oiler's should explore other options. Until then, unless a clearly better option slaps them in the face, I am willing to bet on Dubnyk improving again next season with a better team in front of him.