Change strain reduction to be on first chronological strains

osu.Game.Rulesets.Osu/Difficulty/Evaluators/AimEvaluator.cs

@@ -12,7 +12,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Evaluators
     public static class AimEvaluator
     {
         private const double wide_angle_multiplier = 1.5;
-        private const double acute_angle_multiplier = 2.7;
+        private const double acute_angle_multiplier = 2.6;
         private const double slider_multiplier = 1.35;
         private const double velocity_change_multiplier = 0.75;
         private const double wiggle_multiplier = 1.02;
@@ -90,7 +90,7 @@ public static double EvaluateDifficultyOf(DifficultyHitObject current, bool with
                     // Penalize wide angles if they're repeated, reducing the penalty as the lastAngle gets more acute.
                     wideAngleBonus *= angleBonus * (1 - Math.Min(wideAngleBonus, Math.Pow(calcWideAngleBonus(lastAngle), 3)));
                     // Penalize acute angles if they're repeated, reducing the penalty as the lastAngle gets more obtuse.
-                    acuteAngleBonus *= 0.03 + 0.97 * (1 - Math.Min(acuteAngleBonus, Math.Pow(calcAcuteAngleBonus(lastAngle), 3)));
+                    acuteAngleBonus *= 0.05 + 0.95 * (1 - Math.Min(acuteAngleBonus, Math.Pow(calcAcuteAngleBonus(lastAngle), 3)));
 
                     // Apply wiggle bonus for jumps that are [radius, 3*diameter] in distance, with < 110 angle
                     // https://www.desmos.com/calculator/dp0v0nvowc

osu.Game.Rulesets.Osu/Difficulty/Evaluators/SpeedEvaluator.cs

@@ -14,7 +14,7 @@ public static class SpeedEvaluator
         private const double single_spacing_threshold = OsuDifficultyHitObject.NORMALISED_DIAMETER * 1.25; // 1.25 circles distance between centers
         private const double min_speed_bonus = 200; // 200 BPM 1/4th
         private const double speed_balancing_factor = 40;
-        private const double distance_multiplier = 0.94;
+        private const double distance_multiplier = 0.9;
 
         /// <summary>
         /// Evaluates the difficulty of tapping the current object, based on:

osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs

@@ -160,7 +160,7 @@ private double computeAimValue(ScoreInfo score, OsuDifficultyAttributes attribut
 
             double aimValue = OsuStrainSkill.DifficultyToPerformance(aimDifficulty);
 
-            double lengthBonus = 0.95 + 0.4 * Math.Min(1.0, totalHits / 2000.0) +
+            double lengthBonus = 1 + 0.35 * Math.Min(1.0, totalHits / 2000.0) +
                                  (totalHits > 2000 ? Math.Log10(totalHits / 2000.0) * 0.5 : 0.0);
             aimValue *= lengthBonus;
 
@@ -200,7 +200,7 @@ private double computeSpeedValue(ScoreInfo score, OsuDifficultyAttributes attrib
 
             double speedValue = OsuStrainSkill.DifficultyToPerformance(attributes.SpeedDifficulty);
 
-            double lengthBonus = 0.95 + 0.4 * Math.Min(1.0, totalHits / 2000.0) +
+            double lengthBonus = 1 + 0.35 * Math.Min(1.0, totalHits / 2000.0) +
                                  (totalHits > 2000 ? Math.Log10(totalHits / 2000.0) * 0.5 : 0.0);
             speedValue *= lengthBonus;
 

osu.Game.Rulesets.Osu/Difficulty/Skills/Aim.cs

@@ -26,7 +26,7 @@ public Aim(Mod[] mods, bool withSliders)
 
         private double currentStrain;
 
-        private double skillMultiplier => 25.18;
+        private double skillMultiplier => 23.0;
         private double strainDecayBase => 0.15;
 
         private readonly List<double> sliderStrains = new List<double>();

osu.Game.Rulesets.Osu/Difficulty/Skills/OsuStrainSkill.cs

@@ -13,10 +13,10 @@
     public abstract class OsuStrainSkill : StrainSkill
     {
         /// <summary>
-        /// The number of sections with the highest strains, which the peak strain reductions will apply to.
-        /// This is done in order to decrease their impact on the overall difficulty of the map for this skill.
+        /// The duration strain reduction will apply to.
+        /// We assume that the first seconds of the map are always easier than calculated difficulty due to them being free to retry.
         /// </summary>
-        protected virtual int ReducedSectionCount => 10;
+        protected virtual int ReducedDuration => 40;
 
         /// <summary>
         /// The baseline multiplier applied to the section with the biggest strain.
@@ -37,12 +37,13 @@
             // These sections will not contribute to the difficulty.
             var peaks = GetCurrentStrainPeaks().Where(p => p > 0);
 
-            List<double> strains = peaks.OrderDescending().ToList();
+            List<double> strains = peaks.ToList();
 
-            // We are reducing the highest strains first to account for extreme difficulty spikes
-            for (int i = 0; i < Math.Min(strains.Count, ReducedSectionCount); i++)
+            double reducedSectionCount = ReducedDuration * 1000.0 / SectionLength;
+
+            for (int i = 0; i < Math.Min(strains.Count, reducedSectionCount); i++)
             {
-                double scale = Math.Log10(Interpolation.Lerp(1, 10, Math.Clamp((float)i / ReducedSectionCount, 0, 1)));
+                double scale = Math.Log10(Interpolation.Lerp(1, 10, Math.Clamp((float)i / reducedSectionCount, 0, 1)));
                 strains[i] *= Interpolation.Lerp(ReducedStrainBaseline, 1.0, scale);
             }
 

osu.Game.Rulesets.Osu/Difficulty/Skills/Speed.cs

@@ -15,14 +15,12 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
     /// </summary>
     public class Speed : OsuStrainSkill
     {
-        private double skillMultiplier => 1.430;
+        private double skillMultiplier => 1.44;
         private double strainDecayBase => 0.3;
 
         private double currentStrain;
         private double currentRhythm;
 
-        protected override int ReducedSectionCount => 5;
-
         public Speed(Mod[] mods)
             : base(mods)
         {