[Spoilers] rho21 follows the works of Homer... D'OH!

[rho21]

Turn 28

Score tracking:
Aztec has captured a city state. They haven't gained any pop though, so they produced a settler at the same time.
Kongo has grown a pop in Frikandel, and gained a big culture boost. 2.4 extra per turn compared to last turn; they have taken God of the Open Sky pantheon (bonus from pastures).

Scouting:
The barbarian horseman attacked my slinger, as expected, at 20 v 13. It did 38 damage and took about half that. The slinger moved into Euclid and hit the horseman for 26.
Over in the west, my new slinger uncovers a jade for the coastal wheat city site, then spots an alerted barbarian scout.
The warrior continues its slow voyage of discovery. It is now 4 turns from Euclid. Oh, it discovered a 4th tile with 4 adjacent mountains.  

Housekeeping:
Masonry completed, started on Archery as it's a really good tech to have 1 turn from completion. 3 turns and a slinger kill should get us there.

[Garath]

How did an alerted barbarian scout get there? Can he have seen your borders without you noticing him earlier, or do you think he managed to end up here after being alerted by someone else? Either way, though, there's no way you're going to catch him. Let's hope that one isn't a horse camp as well, if it's coming your way!

[rho21]

It's just about possible it could have seen my capital and made it out again without being spotted. I'm not too worried at this point, even if it does produce horses because I can't see the camp so it must be at a fair distance. Fair chance they'll go elsewhere, and if not I should have enough troops to defend anyway.

The horses coming from the other camp are very interesting, because I can't see any horses in the entire area I've uncovered. Could be a big advantage to have a source somewhere in my back lines. A city roughly where the barbarian camp is could well be a good location.

[rho21]

Turn 29

Score tracking:
Nothing at all of note this turn.

Adventures with barbarians:
The barbarian scout in the west has moved near my slinger, so I take the opportunity to shoot it, for 44 damage. I guess it was alerted by someone else.
In the east, the horseman has moved off to the SE of Euclid. Can't attack it so the warrior moves closer and the slinger spends the turn healing.

Housekeeping:
The route to the wheat is open, so I expend my last builder charge to finish it, which immediately completes Craftsmanship and boosts Irrigation into the bargain. This farm may end up getting pillaged by the horse, but it's still worth it for better policies immediately.

I decide against Euclid working the wheat as it only shaves one turn off the growth time. Possibly an error, but I like the idea of getting the warrior out sooner.

It's also time to switch policies. I decide to swap out God-King for Agoge and keep the other policies (Discipline and Urban Planning) unchanged. This means no Ilkum for the boost to builder production, but (thanks to the horseman delay) the second builder is done next turn at Pythagoras anyway, and I can stick to military for a bit at both cities.

Civics research is changed to Military Tradition which will be done in 8 turns, assuming I can clear that camp by then.

[rho21]

And here's another turn already.

Turn 30

Score tracking:
Kongo finished a fourth tech.

Fun with barbarians:
In the west, the scout crossed a river to move out of range. No point chasing, maybe it'll wander back this way later.
At Euclid, the horseman attacked the city, for some reason. This left it in the red and easily killed by the slinger, which earned a promotion. However there's also a barbarian spearman approaching, which presumably means another unit in the fog guarding the camp. Should be easy pickings if it continues to advance, but may decide to pillage the farm.

Housekeeping:
The second builder is complete; it's time to get the numbers right on the units to follow so I can chop into as close to a full box as possible. I need to chop on turn 34, i.e after 4 more turns of production.

Overflow from the last build I have calculated as 10.4 (from a production of 10.5), but that could well be out by a few tenths as Civ does weird and wonderful things with rounding.
Pythagoras grew this turn, so it now gives 12.6 roduction +50% = 18.9 towards military units. This tallies with the predicted time in the UI of 2 turns for either a warrior (40 ) or a slinger (35 ).

So I have approximately 18.9 * 4 + 10.4 = 86 total to spend. Of course I don't have to spend the whole time building military, and I can pause a build if it's useful.

The best plan is surely going to be to invest two full turns (but not the current overflow) in a warrior, leaving 2.2 to chop. Accordingly, I will build:
T30: Slinger => 29.3
T31: Warrior => 18.9
T32: Warrior => 37.8
T33: Slinger => 48.2 (13.2 overflow)
T34: Warrior gets stone harvest => Campus.

Now, I'm not entirely certain what happens to the 13.2 of overflow from the slinger. Hopefully it overflows from the warrior along with the chop overflow. I've heard worrying things about overflows getting overwritten though, so I may have to run up a test game to test this mechanic out. If it works as hoped, the campus will finish the next turn.

If it doesn't work that way, I'll have to invest a turn into something else to avoid wasting the overflow from the slinger. Probably a granary, as the food boost would be useful here, but getting a little work into the next settler (costs 110 ) wouldn't be a bad plan.

[rho21]

And another one. These Sunday evenings have a really impressive turn rate.

Turn 31

Score tracking:
Aztec gains a fourth population, while Egypt gains a sixth.

Barbarians:
What barbarians? Both scout and spear have moved out of sight. The warrior is back to Euclid next turn and will be joined by a freshly-built one the turn after that ready for the assault on the barbarian camp. I really hope there are two units there to kill.

Housekeeping:
Everything to plan. Archery is switched out with a trickle left, replaced with Bronze Working (currently due in 12, but not yet boosted). The slinger in Pythagoras has 29 invested and is swapped for a warrior.

Euclid seems to be having difficulty deciding which tile to grab next (in 2 turns). The forest W-W looks obvious, or possibly the plain E-E as it's next to truffles. Right now it wants the plain SE-SE instead though, I've no idea why. Perhaps I should look closer at the formula.

No screenshot this turn as there's nothing much to see.

[rho21]

I ran up a test game and determined that the overflow does not get lost in this circumstance.

[Garath]

Excellent.

I've given up trying to understand the tile picker. I thought at least I knew that it picked tiles in order of production, but in a recent solo game it hasn't even been doing that - choosing multiple 2/1 tiles over a 2/2 tile.

So the Aztecs with a capture and a build upcoming are presumably going to be the first to three cities, some time before yours at least are scheduled (after the campus? You have a pretty good amount of military at the moment, to my eyes). Guess he'll be catching up any weakness from that set of comparisons you posted before soon enough. Hopefully he doesn't have too many more convenient city states that he could capture as well!

[rho21]

I've been thinking more about military matters. I agree I'll have plenty on hand for defence and a little scouting by the time I've finished a warrior and slinger in both cities over the next short while.

One possibility is to produce a few hoplites too and go and take Yerevan or Valletta.
Yerevan is virtually useless to me and covers the SE point of my planned expansion (before geopolitics intervenes, anyway). Would be nice to wait for it to build a holy site.
Valletta will soon (when I have an archer) be giving me a little production towards units, but it's not a long-term prospect for survival. Not least because it's pretty central on the map (I assume). From a strategic perspective, a strongpoint there (chop an encampment and walls quickly) would stake a serious claim to all the land north and east of it. It would take some defending though.

Another option is to produce a bunch of settlers. I won't have the production card for these just yet though (maybe 20 turns if I can find another continent), and I don't have enough forests to be chopping them with overflow. I do have a lot of reasonable sites for cities that I want to stake a claim to, the sooner the better.

• The coastal wheat and jade spot WNW of the capital.
  
• C3 to provide defence to the capital's campus.
  
• Another spot further west of that that needs more scouting.
  
• Somewhere on the river SW of C3.
  
• A couple of sites on the same river as Euclid, S and SE of it.
  
• Somewhere on the lake near the barb camp that I suspect will be very fertile.
  
• Two promising spots on the river in the far east.
  
• A pink dot on the river just north of Kongo. Pretty awesome city if I can defend it. They don't know where my capital is, so hopefully they won't be aware how much of a pink dot this is.
  

Wow, 10 plausible sites. 7 of them feel as though they are definitely in my sphere of influence, the others would be more of a stretch. When I have the chance, I'll do screenshots of all these locations.

Another thing that needs doing is improvement and district planning for Euclid and Pythagoras. Do I want a campus at Euclid? If so, it should go down as soon as possible. Quite possibly not, as it doesn't have a great site for one. I was thinking of a commercial district there first.

Suboptimal did a bit of a study of how the tile picker works in the Australia thread for PBEM6. Here's the initial post. I think it got refined a bit beyond this, but one of the key things to take away was that it didn't always work exactly as expected.

Spoiled for length, the game is long done.

Cultural Expansion & Tile Purchase Costs - “Final Version” (for now)

I’m calling this a final version as I’d like to have a fixed base to work against for the duration of this game.  On to “the rules”.

Gold Cost to Buy Tiles

It’s been observed that gold cost goes up the more techs and civics are researched.  After looking at some saves this formula has turned up yet again:

FLOOR(BaseCost * (1 + Multiplier * FLOOR(100 * MAX(CompletedTechs / 67, CompletedCivics / 50))/100))

For 2nd ring tiles the BaseCost = 50 while for 3rd ring tiles BaseCost = 75.  In both cases the value for Multiplier is 4.

What Tile is Being Picked

Calculate the “tile influence” as follows.  The tile with the lowest score is the next tile to be picked.  If multiple tiles share the lowest score the picker will select randomly each turn.

1) Find the distance to the tile from the city center and multiply by 100.  If there is an impassible tile between the target tile and the city center the distance is the shortest number of tiles to get to the target.
2) Add 100 if the tile is beyond the 5th ring.
3) If the tile is a water tile (coast, lake, ocean) add 25.
4) If the tile contains a barbarian camp add 100.
5) If the tile contains an improvement subtract 5.
6) If the tile contains a natural wonder or a resource subtract 105.
7) If the resource is a bonus resource, add 1.
8) Add up the total yields of the tile and subtract the total.  All yields are equal, so that a 4 tile has the same yield as a 2 / 2 tile (both are yield 4).
9) Count the number of tiles that are adjacent to the target tile, are in the 2nd or 3rd ring of the city but not yet claimed and contain a strategic resource or a luxury resource.  Subtract this count from the score.
10) Count the number of tiles that are adjacent to the target tile but not yet claimed and contain a natural wonder.  Subtract this count from the score.
11) Add the terrain influence modifier: 1 for grassland, plains and ocean, 2 for desert, tundra, snow and coast, 3 for mountains
12) Add 1000 if the target tile is not adjacent to any tile already owned by the city in question.

Note that as tiles are claimed by the city the scores may vary due to changes in the value of Step 9.  

I’ll be scoring all of my cities 2nd ring tiles using the above method and we’ll compare the scored results vs. the actual results, tile buys notwithstanding.  When a tile gets rescored because of expansion I’ll note the tile’s new score in the turn report (and update the score in the post with the original scoring).

Here’s Irukandji scored using this method as of my end of Turn 9.  As of right now there are no resources adjacent to the southernmost tiles visible in this picture.



If the game or the city goes long enough there could be a test of the “conventional wisdom” that all 2nd ring tiles are taken before all 3rd ring tiles.  The scoring suggests that the 3rd ring citrus should be taken after all other 2nd ring resource tiles are claimed but before any other 2nd ring tiles.  

I will keep track of successes and failures of these rules in edits below as the game progresses.
-----------------------------------------------------------------------------------------------------------------------------------
T10: Failure.  The scoring picked the NW citrus as the next tile.  The tile picker in-game is taking the wheat tile.
T11: Success?  The picker swapped from the wheat to the SE rice, both of which scored identically.
T13: Success?: The picker seems to have scored both rice tiles and the wheat tile identically (it's flip-flopping between the three)
T20: Success?: Despite never showing the tile in the GUI Irukandji culturally expanded to the NW citrus as predicted by the scoring.  The GUI is now showing the SW rice tile.  As long as that continues to flip-flop amongst the three bonus food tiles all is well.  Cassowary's scoring is here.
T38: Wheat tile at Irukandji is picked - picker was flipping between two rice tiles and the wheat, bought one rice and it grabbed the wheat.  Picker has settled on the remaining rice tile.  After that it should go for the 1/1 plains tile that is adjacent to the horses and jade (scored 197).  If the resource adjacency bonus only counts once then it'll be flip-flopping between that tile and the four tiles that scored 198.
T45: Cassowary takes the iron tile (win).  Its next tile is the 1/1 plains NW of jade.  The tile should is scored at 199 once the jade is controlled.  I have to check if there's flip-flopping because there's three tiles at 198 if the jade matters, one at 198 and two at 199 if it doesn't.
T50: Founded Mouse Spider and scored it out.  Should go citrus->citrus->rice (if available).  Cassowary is dead set on the same tile NW of the jade and has not flip-flopped.
T51: Citrus at Mouse Spider should be scored one lower.  Tile picker has selected the western unclaimed citrus.
T56: Irukandji and Mouse Spider both expand to the expected tiles and select the remaining lowest scoring tile for the next expansion.
T60: Blue-Ringed Octopus founded & scored.  Fish tile should be first.
T61: Blue-Ringed Octopus is choosing the fish first.
T65: Mouse Spider has grabbed all citrus, now choosing the 1/2 plains to the east.

[rho21]

Turn 32

Score tracking:
A new Aztec city was placed this turn, taking them into a share of the score lead, such as that matters.
Kongo jumped up by 26 points of military strength. I'm pretty sure this isn't a warrior + healing as their strength would be above the calculated maximum strength. So perhaps scout + slinger or even two slingers.

Barbarians:
The spear is back, chilling outside Euclid. Next turn the warrior will be finished and the advance will begin.

Housekeeping:
Euclid grew to size 2 and is now working the wheat.