Your question as to the best size of the data set is the core of the matter. Vis, how much data is enough until all game modes and combinations of play cross a global player base is enough to start adjusting the game for the better.
The basic process the DEV follow is;
- collect data to identify tweak class and extent is required.
- build the tweak and test tweaks in a test environment
- adjust tweaks in test for unexpected side effects
- some devs then tea tweaks in semi wild environment
- adjusting again if required
- if tweak type is suitable for hotfix only, vis pre xbl approved for release, then release.
- if tweak type does not fit hotfix class, ie a patch, then get tweaks are packaged up and sent to Microsoft xbl for assessment
- xbl need to determine that patch will not impact xbl, other xbl products and their millions of users and associated product devs.
- xbl traditionally require 4-6 weeks to assess and if OK approve a patch for release.
- if xbl says adjustments are required, then the devs adjust patch retest, repack and send to xbl....rinse and repeat you get it
- once xbl say all OK then its released on xbl.
Big and long winded process isn't it.
Xmas sales bring a whole new group of people to CoD. A big influx can have the effect of changing multiplayer dynamics, think about server loads and effects on lag, match making, spawns and this in turn on DLC under final design approval as just one facet.
It is prudent for devs with a weeks 2 Nov release and big at release on line player bases to wait the 6 weeks for the next influx of multi players users, let the play dynamics and server loads settle and then collect post Xmas influx data and opinions as key inputs into tweak decisions.
Once this is done the tweak and 3arc/xbl approval and release cycles can take 4-8 weeks.
To lay it out in summary form for say a garden variety patch with CoD;
Release. Wk2 Nov
Collect data. Wk3 Nov - wk4 Dec
Xmas influx.. Wk4 Dec
Collect data. Wk4 Dec-wk2 jan
DEV tweak. Wk3 jan-wk4 jan
3arc testing. Wk4 Jan
Xbl assessment Wk1 Feb - wk4 Feb
Release patch Wk4 Feb
If tweaks are simple and can be done by hotfix (no xbl approval and couple variable changes and no core code changes) then this could occur by week 2-3 Jan.
Hope this makes sense and is helpful.
Like all folks I would love tweaks to be released faster but there is little point making a tweak that makes the game worse.
Cheers