Hmmm yes overcomplexity in formulas is bad... looking into the problem presented by my/Aesons examples a bit more... remember we had:
Player 1 conquers the world at 840AD. Lucky's 840AD conquest was the earliest in GOTM05. Total Score is 6017. Victory condition wasn't met.
Overall% = 0.271
Player 2 (fastest launch) launches their spaceship in 1810AD. In GOTM05, Nathan Barclay got a score of 3027 for a 1810AD launch. Victory condition was met in 370 turns.
Overall% = 0.803
Player 3 (highest score) conquers early and milks their score until a 2050AD launch. In GOTM05 SirPleb had the highest score with 7412 from a 2050 milked game. Victory condition was met in 540 turns.
Overall% = 0.790
Player 4 (2nd fastest lauch) launches say after 380 turns with a slightly higher (due to more turns) score than Player 2 of say 3100.
Overall% = 0.788
Examining the formula
OverallPercentage = ((MapSize * TurnsPercentage) + ScorePercentage) / (MapSize + 1)
TurnsPercentage = FewestTurns / PlayerTurns
ScorePercentage = PlayerScore / HighestScore
MapSize: 80% Water / 70% Water / 60% Water
Tiny: 1.00 / 1.50 / 2.00
Small: 1.33 / 2.00 / 2.66
Standard: 2.77 / 4.16 / 5.55
Gives for this example with MapSize = 2
Overall% = (2 * Turns%) + Score% ) / 3
The main problem in this example is that with a tiny 60% water map and a MapSize of 2, Score% is up to 1/3 of the Overall%.
With say a standard 70% water map with MapSize = 4.16 gives
Overall% = (4.16 * Turns%) + Score% ) / 5.16
Which means that for this example Score% can be at most 1/5.16 of the Overall%.
The problem would be even worse on a tiny 80% water map and MapSize of 1, with the Score% making up to 1/2 of the Overall%... which means it would be quite possible for a "milked" victory to beat the "fastest" victory.
A simple solution may be to simply double the MapSize multipliers to reduce the effect of the Score% on Overall%
In our example doubling the MapSize to 4 gives the following:
Player 1 conquers the world at 840AD with 6017 score.
Overall% = 0.203
Player 2 (fastest launch) launches their spaceship in 1810AD with 3027 score.
Overall% = 0.882
Player 3 (highest score) conquers early and milks their score to 7412 and a 2050AD launch.
Overall% = 0.748
Player 4 (2nd fastest lauch) launches say after 380 turns with a score of say 3100.
Overall% = 0.863
No Problem!
(For an exercise to see how MapSize affects Overall% try the examples above with the unmodified MapSize of 1 for a tiny 80% water map... the milked Player3 beats the fastest Player 2... you do the math)
Mind you doubling the MapSize modifiers with a standard 60% water map the Score% would make up about 9% of the Overall%... which is fine by me as after all the idea is to "race" to the specified victory condition isn't it?