Pretty standard deal looking at the percentages. Worth of noting is that cap is rumoured to be going up couple millions for next year too, so this propably drops From 11.3% -> somewhere around 10,95%.
Heres some comparables;
PLAYER CAP PERCENTAGE (SIGNED @ AGE) PPG / CONTRACT LENGTH
Toews 14,7% (2015, @ 27 years) PPG 0,9 / Contract 8 years
P. Kane 14,7% (2015, @ 27 years) PPG 0,97 / Contract 8 years
Panarin 14,2% (2019, @ 28 years) PPG 0,99 / Contract 7 years
Malkin 13,8% (2014, @ 26 years) PPG 1,22 / Contract 8 years
Tavares 13,8% (2018, @ 28 years) PPG 0,92 / Contract 7 years
Kopitar 13,7% (2016, @ 29 years) PPG 0,9 / Contract 8 years
Benn 12,7% (2017, @ 28 years) PPG 0,88 / Contract 8 years
Seguin 12,1% (2019, @ 26 years) PPG 0,87 / Contract 8 yeras
Giroux 12,1% (2014, @ 26 years) PPG 0,91 / Contract 8 years
Stone 11,7% (2019, @ 27 years) PPG 0,84 / Contract 8 years
Voracek 11,3% (2016, @ 27 years) PPG 0,86 / Contract 8 years
Backstrom ~11,3 % (2020, @ 32 years) PPG 0,97 / Contract 5 years
Skinner 11% (2019, @ 27 years) PPG 0,67 / Contract 8 years
Johansen 10,7% (2017, @ 25 years) PPG 0,76 / Contract 8 years
ROR 10,3% (2016, @ 25 years) PPG 0,83 / Contract 7 years
Wheeler 10,1% (2019, @ 33 years) PPG 0,81 / Contract 5 years
Couture 9,8% (2019, @ 30 years) PPG 0,8 / Contract 8 years
Duchene 9,8% (2019, @ 28 years) PPG 0,74 / Contract 7 years
Hayes 8,8% (2019, @ 27 years) PPG 0,6 / Contract 7 years
JVR 8,8% (2018, @ 29 years) PPG 0,65 / Contract 5 years
E. Kane 8,8% (2018, @ 27 years) PPG 0,62 / Contract 7 years
Lee 8,6% (2019, @ 29 years) PPG 0,61 / Contract 7 years
Pavelski 8,6% (2019, @ 35 years) PPG 0,79 / Contract 3 years
Pacioretty 8,6% (2019, @ 31 years) PPG 0,71 / Contract 4 years
As you can see From this list Backstrom has 3rd highest career PPG before signing his new contract and he is 12th on the percentage-list. I didnt account U25 signed contracts, or before 2014.
Obviously the reason Backs isnt third on the list like his career PPG would suggest, there is the regression propability with the age. But to be right where his percentages are he is totally fine regressing to 0,8 PPG player (which he actually pretty much already is), and even if he regresses to 0,6-0,7 PPG player he is Still overpaid "only" roughly by a million or two. Thats fine for a franchise legend.
Most of this list were younger (26-29) when signing their contracts, but also factor in that those contracts are 2-3 years longer. Adding 3 years to this contract likely brings it down to Couture numbers, and that seems fair to me.
Count in that for the last 4-5 years he has been one of the most team-friendly contracts in the league, he deserved not to give a hometown discount. Which is something I see most were expecting (I was hoping for it too). While this is not home discount -deal, its a fair one.
Negative side is the structure of the contract. Its pretty much untradable before september 2025, after the last signing bonus is paid off. No cap floor team is going to take that 6 million bonus to their hands. But as the expecations are that he will retire in Washington anyways, why would you mind about how hard it is to trade him. Its Under 35 contract, people are keen to get rashes and other injuries if they just cant keep up.
Conclusion; This deal gets 92% approval rate From Roshi.
** I dont guarantee the numbers on this post are necessarily correct, I checked those on a rush, but they can give quite a decent guideline.