The correlation between kda and Win Rate is 0.85. The more kda, the more Win Rate, and vice versa. But some values are higher than expected, some are lower. Efficiency is a difference between the value of Win Rate depending on kda (blue dots) with respect to the expected value (red line).
Efficiency
Book Of The Dead 0.0444
Stormcrafter 0.0360
Telescope 0.0340
Arcanist'S Armor 0.0316
Trusty Shovel 0.0230
Ascetic'S Cap 0.0204
Seeds Of Serenity 0.0194
Ceremonial Robe 0.0183
Arcane Ring 0.0163
Timeless Relic 0.0151
Martyr'S Plate 0.0146
Giant'S Ring 0.0071
Havoc Hammer 0.0053
Eye Of The Vizier 0.0053
Bullwhip 0.0045
Psychic Headband 0.0036
Dandelion Amulet 0.0031
Cloak Of Flames 0.0027
Faded Broach 0.0020
Lance Of Pursuit -0.0004
Fairy'S Trinket -0.0006
Mirror Shield -0.0025
Pig Pole -0.0028
Occult Bracelet -0.0029
Seer Stone -0.0030
Gossamer Cape -0.0036
Dragon Scale -0.0052
Apex -0.0055
Defiant Shell -0.0062
Broom Handle -0.0065
Mind Breaker -0.0066
Spark Of Courage -0.0069
Stygian Desolator -0.0071
Force Boots -0.0099
Philosopher'S Stone -0.0103
Vampire Fangs -0.0103
Ninja Gear -0.0108
Trickster Cloak -0.0115
Book Of Shadows -0.0128
Duelist Gloves -0.0138
Pupil'S Gift -0.0165
Pirate Hat -0.0173
Paladin Sword -0.0174
Ogre Seal Totem -0.0203
Grove Bow -0.0203
Vambrace -0.0247
Elven Tunic -0.0248
Enchanted Quiver -0.0255