If you go back to those other years, the PS3 was outselling the 360 in the early months of the year by the same margins that you have mentioned.  True, the 360 did have a better market position in the US before.  I think that the US market is starting to stabalise for the XB1 and like I said, M$ will do whatever it takes to bring the US market back to atleast parity if not in favor of the XB1.

I would think that the english speaking concept is true.  That only falls in line with what I am saying.  The big increases match with the large amount of big shooter titles that come out at the end of each year.  Because the XB1 has a console exclusive shooter coming out this holiday season, it will entice people to go that route.  Heck, we have seen a number of people talking about picking up the XB1 this holiday even though they already have the PS4 just to get it.  With Battlefield being pushed to next year, that is one less reason to go with the PS4 - even though it was not console exclusive.  Every console exclusive title gains more traction when the 3rd party titles move to a leter date.

I will say it again, the PS4 should still outsell the XB1 worldwide this holiday season by a long shot.  But, in the US, November and December could be 50/50 or even move to the XB1 ide of things.

Not that I disagree with any of that, let's do a little bit of math, and keep it (a little overly) simple. Let's say the English speaking world makes up 50% of the world console market (which is roughly true, this gen so far US makes up 47% of all 8th gen console sales), and also assume that the holiday period surges are exclusive to that English speaking regions (50%). Additionally I will assume X360 and PS3 sold at equal quantities.

Assumptions :

1) non-English speaking countries' surges are more evenly distributed
2) English speaking world takes up 50% of the world console market share
3) The quantities sold double from first half to second half on average
4) X360 and PS3 sold at equal quantities
5) Market Shares are rounded to 60%-40% in English speaking world, and 40%-60% in non-English ones

In the earlier gen, X360 had a roughly 60% share versus the 40% of PS3. Let's say the surge gives an extra 50% boost (on top of the usual 50% boost everywhere). The surges between 2 halves are distributed more evenly in the non-English world compared to English speaking ones. Basically this is what happened in the 7th generation:

7th generation annual sales fluctuations (on average, in percentages)

X360
English : 60 surges to 120 => total 180 (60%), DOUBLES
n-English : 48 surges to 72 => total 120 (40%), 50% INCREASE
1st half sales :  60 + 48 = 108
2nd half sales :  120 + 72 = 192
Increase factor : 1.78x (+78%)

PS3
English : 40 surges to 80 => total 120 (40%), DOUBLES
n-English : 72 surges to 108 => total 180 (60%), 50% INCREASE
1st half sales :  40 + 72 = 112
2nd half sales :  80 + 108 = 188
Increase factor : 1.68x (+68%)

Now, let's repeat the same scenario with due market share adjustments (in 8th gen)

Assumptions
1, 2, 3) The same as above
4) Quantities at this stage are irrelevant, dealing with percentages
5) Market Shares are rounded to 40%-60% in English speaking world (favoring PS4), and 25%-75% in non-English ones

8th generation annual sales fluctuations (on average, in percentages)

XB1
English : 40 surges to 80 => total 120 (61%), DOUBLES
n-English : 30 surges to 45 => total 75 (39%), 50% INCREASE
1st half sales :  40 + 30 = 70
2nd half sales :  80 + 45 = 125
Increase factor : 1.79x (+79%)

PS4
English : 60 surges to 120 => total 180 (44%), DOUBLES
n-English : 90 surges to 135 => total 225 (56%), 50% INCREASE
1st half sales :  60 + 90 = 150
2nd half sales :  120 + 135 = 255
Increase factor : 1.70x (+70%)

Comparison of Increase factors
X360 : 1.78
PS3 : 1.68
XB1 : 1.79
PS4 : 1.70

Seems like the increase factors are virtually unchanged but the gap between PS4 and XB1 has slightly decreased. As long as Xbox leans more on the US side of the equation, the increase factor will benefit them relatively more . So in the main analysis, the expected values for PS4 may be a bit lower (more in lines with the original estimate, instead of shift up), and a bit higher for the XB1 (but still within the given range).

Your hope is shooters is misplaced, PS4 and X1 were tied there with ghosts and BF4.  But Wolfenstein numbers show X1 has even managed to even lose 360 ardent FPS advantage.

PS4 550k X1 290k.  Worse PS4 version out sold the X1 in NA, 200k to 170k.  Not a big number but telling where the shooter market is headed.  And its towards PS4 not X1.

The shooter that I alluded to was the Halo MCC.  Because it is exclusive and it draws at the heartstrings of every Xbox fan, it has a bigger factor than ANY 3rd party title.  The MCC isn't the end all, but it is a system exclusive shooter that can bring some of the early adopters back to the platform and those just getting ready to join in are likely to jump on board with the XB1 until the PS4 has more exclusives towards the end of 2015. 

I would have to look up the numbers on COD and BF on the XB1/PS4, but i will just have to believe you.  I assume that you mean that the sales of the PS4 version of these games are 60% to PS4 and 40 % to XB1 to match what we are discussing.  If they are total units equal, then you just proved the exact opposite based on install base of the PS4 vs the XB1.

all irrelevant! We are looking at the first Xbox console without a Halo game. Its a wildcard!
and that white Destiny bundle is going to sell in masses.
but interesting stuff.

Wishfull thinking nothing more there, you are hopiong remakes make a big difference.  It wont.  Sure it will pull at the heart strings of x 1owners but it wont change minds of people choosing which console to buy.  Its not Halo5 stop pretanding it is.  

User base proves nothing, those two games did majority of their sales at launch when they two consoles sold similar numbers.