About a year ago (before the earth swallowed up large portions of the city and life got a little hectic) I posted a fairly in depth analysis of the whole BR vs BB thing. The results were interesting. There is a fairly huge flaw in the BR concept as portrayed in canon, but its probably not what most people would think of. The flaw is building tenders carrying multiple riders. The better option is one rider per tender.
I've reposted the my analysis (it was in two messages) below. The raw files and the spreadsheet with the detailed analysis are on the ct-starships site.
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I'd always thought this was an open and shut thing, but I've been playing a few
TCS campaigns lately and some doubts had been creeping into my mind. To cut a
long story short, while it was fairly obvious that the rider was almost always
cheaper than the ship, there was another factor at play. Namely how much of your
budget you can spend on capital ship. So I decided to do a proper analysis and
see. I've uploaded the results. They are interesting I think.
I made the following assumptions.
A navy can spend 35% of its budget on capital ships. However riders require
extra escorts to cover them if they need to withdraw, so you can only spend 30%
on riders to cover this. Also a navy has to spend about 25% of its budget on
cruisers, but when the size of a capital ship drops to 70,000Td or less, the
cruiser and capital ship start to overlap. Therefore when this happens, the navy
can spend 50% of its budget on capital ships (dropping to 45% for riders).
There are two fleets High end and Low end. High end have armour 11 and agility
6. Low end have armour 4 and agility 5. All carry the biggest spinal meson
available.
I also included a hybrid design, a fleet tender carrying a jump 1 capable rider,
allowing it to cover its own tenders if the fleet has to withdraw.
Rather than use an abstract budget to determine affordability, I have created two theoretical states.
State One
world 1 - Industrial, 20 Billion pop at max tech level with A starport
world 2 - 5 Billion pop at tech level -1 with A starport
World 3 - 5 Billion pop at tech level -1 with B starport
Misc worlds - 1 Billion pop at tech level -2 with C starport
This represents a multiworld pocket empire who's influence would be felt sector wide
State Two
Single world - Rich, 800 Million pop at max tech level
This represents a powerful minor world who's influence would be felt subsector wide.
Looking at my adjusted results, it would seem the low end battlehip is about the
best investment at jump 3 and below, and gives the riders a good run at jump 4
(and the high end jump 4 battleship is just plain unaffordable for any state
other than the Imperium, Zhodani, Solomani Confederation etc).
I'm planning to expand and look at lower tech levels.
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Well I've finally finished my attempted analysis. Its interesting. First thing
that jumps out is the utter pointlessness of the multi rider tenders. There
advantages are just too slight to compensate for their disadvantages (basically
blow up and strand an entire squadron). It would seem that every single major
power in Traveller has based its fleets on a faulty premise

.
Next thing that hit me was the futility of high end/high jump battleships. They
are just too expensive (at TL15 you can get six times as many jump 4 high end
riders as ships). However, interestingly, at the low end, the battleship very
rapidly becomes an attractive option. At TL15 jump 3 you get 2182 ships to 2117
riders.
As expected, the advantages of the rider drops off rapidly as jump numbers and
TL's drop. When you hit the jump 2-3 range, the ships tend to become the better
option.