Average Floor Science

I wrote a mod to count the number of rooms on a floor, and then restart the game, and continue doing that for 10,000 iterations. This allows us to see the average number of rooms per floor and if the different kinds of stages have any effect.

Results:
- The average number of rooms on floor 1 is 9.5. The stage type makes no difference.
- The average number of rooms on Basement 2, Cellar 2, and Burning Basement 2 is 12.6.
- The average number of rooms on Downpour 2 and Dross 2 is 12.7. This is probably due to the floor generation algorithm having to place the mirror room.
- The average number of rooms on floor 3 is 15.7. The stage type makes no difference.

Conclusions:
- On Basement 1 / Cellar 1 / Burning Basement 1, you might want to spend an extra key to go to Downpour 1 / Dross 1. In return, the floor will have 3 less rooms on average, but the enemies will be harder to dodge and the boss will be harder.
- On Basement 2 / Cellar 2 / Burning Basement 2, you probably will want to spend an key to go to Downpour 2 / Dross 2. In return, the floor will have 3 less rooms on average, but the enemies will be harder to dodge and the boss will be harder (on average).
- Another factor to consider is that the alt paths have two items in the Treasure Room, but this is most irrelevant as:
  - 1) You may not find the Treasure Room while on the way to the boss.
  - 2) You may not have a key to open the Treasure Room (especially since you just used one to enter the alt floor).
  - 3) The average expected value of the Treasure Room is extremely low.





Full data is below.

Floor 1 - Basement 1:
  Total floors: 10000
  Total rooms: 95094
  Average: 9.51
  Room count of 8: 1547 (15.47%)
  Room count of 9: 4111 (41.11%)
  Room count of 10: 2602 (26.02%)
  Room count of 11: 1236 (12.36%)
  Room count of 12: 450 (4.5%)
  Room count of 13: 53 (0.53%)
  Room count of 14: 1 (0.01%)

Floor 1 - Cellar 1:
  Total floors: 10000
  Total rooms: 95050
  Average: 9.51
  Room count of 8: 1490 (14.9%)
  Room count of 9: 4180 (41.8%)
  Room count of 10: 2628 (26.28%)
  Room count of 11: 1256 (12.56%)
  Room count of 12: 384 (3.84%)
  Room count of 13: 62 (0.62%)

Floor 1 - Burning Basement 1:
  Total floors: 10000
  Total rooms: 95054
  Average: 9.51
  Room count of 8: 1474 (14.74%)
  Room count of 9: 4182 (41.82%)
  Room count of 10: 2660 (26.6%)
  Room count of 11: 1244 (12.44%)
  Room count of 12: 380 (3.8%)
  Room count of 13: 60 (0.6%)

Floor 1 - Downpour 1:
  Total floors: 10000
  Total rooms: 94928
  Average: 9.49
  Room count of 8: 1534 (15.34%)
  Room count of 9: 4126 (41.26%)
  Room count of 10: 2709 (27.09%)
  Room count of 11: 1192 (11.92%)
  Room count of 12: 388 (3.88%)
  Room count of 13: 50 (0.5%)
  Room count of 14: 1 (0.01%)

Floor 1 - Dross 1:
  Total floors: 10000
  Total rooms: 95050
  Average: 9.51
  Room count of 8: 1494 (14.94%)
  Room count of 9: 4131 (41.31%)
  Room count of 10: 2711 (27.11%)
  Room count of 11: 1228 (12.28%)
  Room count of 12: 368 (3.68%)
  Room count of 13: 67 (0.67%)
  Room count of 14: 1 (0.01%)

Floor 2 - Basement 2:
  Total floors: 10000
  Total rooms: 126118
  Average: 12.61
  Room count of 11: 1680 (16.8%)
  Room count of 12: 3746 (37.46%)
  Room count of 13: 2332 (23.32%)
  Room count of 14: 1464 (14.64%)
  Room count of 15: 599 (5.99%)
  Room count of 16: 154 (1.54%)
  Room count of 17: 25 (0.25%)

Floor 2 - Cellar 2:
  Total floors: 10000
  Total rooms: 125983
  Average: 12.6
  Room count of 11: 1643 (16.43%)
  Room count of 12: 3799 (37.99%)
  Room count of 13: 2432 (24.32%)
  Room count of 14: 1366 (13.66%)
  Room count of 15: 593 (5.93%)
  Room count of 16: 152 (1.52%)
  Room count of 17: 15 (0.15%)

Floor 2 - Burning Basement 2:
  Total floors: 10000
  Total rooms: 126076
  Average: 12.61
  Room count of 11: 1629 (16.29%)
  Room count of 12: 3781 (37.81%)
  Room count of 13: 2443 (24.43%)
  Room count of 14: 1361 (13.61%)
  Room count of 15: 619 (6.19%)
  Room count of 16: 152 (1.52%)
  Room count of 17: 15 (0.15%)

Floor 2 - Downpour 2:
  Total floors: 10000
  Total rooms: 127085
  Average: 12.71
  Room count of 9: 2 (0.02%)
  Room count of 10: 142 (1.42%)
  Room count of 11: 1019 (10.19%)
  Room count of 12: 2574 (25.74%)
  Room count of 13: 4195 (41.95%)
  Room count of 14: 2008 (20.08%)
  Room count of 15: 57 (0.57%)
  Room count of 16: 3 (0.03%)

Floor 2 - Dross 2:
  Total floors: 10000
  Total rooms: 127116
  Average: 12.71
  Room count of 9: 2 (0.02%)
  Room count of 10: 144 (1.44%)
  Room count of 11: 1009 (10.09%)
  Room count of 12: 2545 (25.45%)
  Room count of 13: 4249 (42.49%)
  Room count of 14: 1985 (19.85%)
  Room count of 15: 64 (0.64%)
  Room count of 16: 2 (0.02%)

Floor 3 - Caves 1:
  Total floors: 10000
  Total rooms: 156895
  Average: 15.69
  Room count of 15: 4093 (40.93%)
  Room count of 16: 5246 (52.46%)
  Room count of 17: 415 (4.15%)
  Room count of 18: 188 (1.88%)
  Room count of 19: 37 (0.37%)
  Room count of 20: 19 (0.19%)
  Room count of 21: 2 (0.02%)

Floor 3 - Catacombs 1:
  Total floors: 10000
  Total rooms: 156851
  Average: 15.69
  Room count of 15: 4083 (40.83%)
  Room count of 16: 5291 (52.91%)
  Room count of 17: 385 (3.85%)
  Room count of 18: 182 (1.82%)
  Room count of 19: 52 (0.52%)
  Room count of 20: 6 (0.06%)
  Room count of 21: 1 (0.01%)

Floor 3 - Flooded Caves 1:
  Total floors: 10000
  Total rooms: 156836
  Average: 15.68
  Room count of 15: 4102 (41.02%)
  Room count of 16: 5280 (52.8%)
  Room count of 17: 377 (3.77%)
  Room count of 18: 178 (1.78%)
  Room count of 19: 49 (0.49%)
  Room count of 20: 12 (0.12%)
  Room count of 21: 2 (0.02%)

Floor 3 - Mines 1:
  Total floors: 10000
  Total rooms: 156869
  Average: 15.69
  Room count of 15: 4047 (40.47%)
  Room count of 16: 5328 (53.28%)
  Room count of 17: 404 (4.04%)
  Room count of 18: 160 (1.6%)
  Room count of 19: 52 (0.52%)
  Room count of 20: 9 (0.09%)

Floor 3 - Ashpit 1:
  Total floors: 10000
  Total rooms: 156806
  Average: 15.68
  Room count of 15: 4046 (40.46%)
  Room count of 16: 5368 (53.68%)
  Room count of 17: 390 (3.9%)
  Room count of 18: 137 (1.37%)
  Room count of 19: 48 (0.48%)
  Room count of 20: 11 (0.11%)




Floor 3 - Caves 1 (Hard Mode):
  Total floors: 10000
  Total rooms: 180384
  Average: 18.04
  Room count of 17: 2353 (23.53%)
  Room count of 18: 5021 (50.21%)
  Room count of 19: 2546 (25.46%)
  Room count of 20: 57 (0.57%)
  Room count of 21: 16 (0.16%)
  Room count of 22: 6 (0.06%)
  Room count of 23: 1 (0.01%)




Here's a copy of the mod used:




-- Constants
local MOD_NAME = "floor-average-finder"
--local WARP_COMMAND = "stage 2b"
local STAGE = 1
local STAGE_TYPE = 0
local MAX_ROOM_INDEX = 168

local mod = RegisterMod(MOD_NAME, 1)
local game = Game()
local sfx = SFXManager()
local totalFloors = 0
local totalRooms = 0
local roomMap = {}

local isEnabled = true

-- From: http://lua-users.org/wiki/SimpleRound
local function round(num, numDecimalPlaces)
  return tonumber(string.format("%." .. (numDecimalPlaces or 0) .. "f", num))
end

-- From: https://stackoverflow.com/questions/33510736
local function hasValue(t, val)
  for index, value in ipairs(t) do
    if value == val then
      return true
    end
  end

  return false
end

function mod:postRender(player)
  if isEnabled then
    Isaac.ExecuteCommand("restart")
  end
end

function mod:postNewLevel(player)
  local level = game:GetLevel()
  local stage = level:GetStage()
  local stageType = level:GetStageType()

  if stage ~= STAGE or stageType ~= STAGE_TYPE then
    return
  end

  totalFloors = totalFloors + 1

  -- getNumRooms
  local roomSafeIndexes = {}
  for i = 0, MAX_ROOM_INDEX do
    local room = level:GetRoomByIdx(i)
    if room ~= nil then
      local data = room.Data
      if data ~= nil then
        if (
          data.Type ~= RoomType.ROOM_SECRET
          and data.Type ~= RoomType.ROOM_SUPERSECRET
          and data.Type ~= RoomType.ROOM_ULTRASECRET
          and not hasValue(roomSafeIndexes, room.SafeGridIndex)
        ) then
          roomSafeIndexes[#roomSafeIndexes + 1] = room.SafeGridIndex
        end
      end
    end
  end
  local numRooms = #roomSafeIndexes

  totalRooms = totalRooms + numRooms
  if roomMap[numRooms] == nil then
    roomMap[numRooms] = 0
  end
  roomMap[numRooms] = roomMap[numRooms] + 1

  Isaac.DebugString("Total floors: " .. tostring(totalFloors))
  Isaac.DebugString("Total rooms: " .. tostring(totalRooms))
  local average = round(totalRooms / totalFloors, 2)
  Isaac.DebugString("Average: " .. tostring(average))

  local sortedKeys = {}
  for k, v in pairs(roomMap) do
    sortedKeys[#sortedKeys + 1] = k
  end
  table.sort(sortedKeys)
  for _, sortedKey in ipairs(sortedKeys) do
    local roomCount = roomMap[sortedKey]
    local averagePercent = round((roomCount / totalFloors) * 100, 2)
    Isaac.DebugString(
      "Room count of " .. tostring(sortedKey) .. ": " .. tostring(roomCount)
      .. " (" .. averagePercent .. "%)"
    )
  end

  if totalFloors >= 10000 then
    isEnabled = false
    sfx:Play(SoundEffect.SOUND_ANGEL_BEAM)
  end
end

function mod:postGameStarted()
  local seeds = game:GetSeeds()
  if seeds:HasSeedEffect(SeedEffect.SEED_PREVENT_ALL_CURSES) then
    --Isaac.ExecuteCommand(WARP_COMMAND)
  else
    Isaac.DebugString("ERROR: Turn on BLCK CNDL Easter Egg.")
  end
end

mod:AddCallback(ModCallbacks.MC_POST_RENDER, mod.postRender)
mod:AddCallback(ModCallbacks.MC_POST_NEW_LEVEL, mod.postNewLevel)
mod:AddCallback(ModCallbacks.MC_POST_GAME_STARTED, mod.postGameStarted)

Isaac.DebugString(MOD_NAME .. " initialized.")