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Ranking formula refinements (#3288)

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* Reduce the maximum scaling time from 600s to 500s

8m20s is already much longer than nearly all ranked races will be, so it matters most for eliminated players. It would be too punishing if kept to 600 with the new time scaling method.

* New helper function for ranking computations

* Make short races less important for ranking points

And long races more important
This commit is contained in:
Alayan-stk-2 2018-06-09 10:43:19 +02:00 committed by Benau
parent 05572b0084
commit 7c14fd28ba
2 changed files with 17 additions and 6 deletions
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20
src/network/protocols/server_lobby.cpp
View File

@ -970,13 +970,13 @@ void ServerLobby::computeNewRankings()
{
result = 0.0;
ranking_importance = mode_factor *
MAX_SCALING_TIME * MAX_POINTS_PER_SECOND * player_factors;
scalingValueForTime(MAX_SCALING_TIME) * player_factors;
}
else if (!players[j])
{
result = 1.0;
ranking_importance = mode_factor *
MAX_SCALING_TIME * MAX_POINTS_PER_SECOND * player_factors;
scalingValueForTime(MAX_SCALING_TIME) * player_factors;
}
else
{
@ -994,10 +994,11 @@ void ServerLobby::computeNewRankings()
(player1_time - player2_time) / (player2_time / 20.0);
result = std::max(0.0, 0.5 - result);
}
float max_time = std::min(std::max(player1_time, player2_time),
MAX_SCALING_TIME);
ranking_importance = mode_factor *
std::min(
std::max(player1_time, player2_time), MAX_SCALING_TIME) *
MAX_POINTS_PER_SECOND * player_factors;
scalingValueForTime(max_time) * player_factors;
}
// Compute the ranking change
scores_change[i] +=
@ -1070,6 +1071,15 @@ double ServerLobby::getModeSpread()
return 1.4;
} // getModeSpread
//-----------------------------------------------------------------------------
/** Compute the scaling value of a given time
* Short races are more random, so we don't use strict proportionality
*/
double ServerLobby::scalingValueForTime(float time)
{
return time * sqrt(time/120.0) * MAX_POINTS_PER_SECOND;
} // scalingValueForTime
//-----------------------------------------------------------------------------
/** Manages the distribution of the base points.
* Gives half of the points progressively

3
src/network/protocols/server_lobby.hpp
View File

@ -106,7 +106,7 @@ private:
/* Ranking related variables */
// If updating the base points, update the base points distribution in DB
const double BASE_RANKING_POINTS = 4000.0;
const double MAX_SCALING_TIME = 600.0;
const double MAX_SCALING_TIME = 500.0;
const double MAX_POINTS_PER_SECOND = 0.125;
/** Online id to profile map, handling disconnection in ranked server */
@ -197,6 +197,7 @@ private:
double distributeBasePoints(uint32_t online_id);
double getModeFactor();
double getModeSpread();
double scalingValueForTime(float time);
void checkRaceFinished();
public: