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 0.0463
Telescope 0.0421
Stormcrafter 0.0412
Arcanist'S Armor 0.0323
Ceremonial Robe 0.0209
Ascetic'S Cap 0.0198
Giant'S Ring 0.0179
Trusty Shovel 0.0179
Seeds Of Serenity 0.0172
Timeless Relic 0.0159
Arcane Ring 0.0159
Martyr'S Plate 0.0153
Spell Prism 0.0138
Bullwhip 0.0105
Psychic Headband 0.0104
Dandelion Amulet 0.0102
Havoc Hammer 0.0084
Quickening Charm 0.0063
Eye Of The Vizier 0.0062
Cloak Of Flames 0.0036
Seer Stone 0.0022
Fallen Sky -0.0003
Faded Broach -0.0010
Tumbler'S Toy -0.0016
Stygian Desolator -0.0017
Defiant Shell -0.0019
Gossamer Cape -0.0030
Force Boots -0.0033
Occult Bracelet -0.0033
Fairy'S Trinket -0.0037
Penta-Edged Sword -0.0043
Apex -0.0049
Mirror Shield -0.0050
Dragon Scale -0.0054
Lance Of Pursuit -0.0055
Mind Breaker -0.0060
Pig Pole -0.0086
Pirate Hat -0.0090
Philosopher'S Stone -0.0090
Vampire Fangs -0.0094
Spark Of Courage -0.0099
Book Of Shadows -0.0111
Trickster Cloak -0.0119
Ninja Gear -0.0132
Paladin Sword -0.0146
Ogre Seal Totem -0.0148
Broom Handle -0.0151
Grove Bow -0.0169
Pupil'S Gift -0.0176
Duelist Gloves -0.0181
Ring Of Aquila -0.0189
Enchanted Quiver -0.0200
Titan Sliver -0.0240
Elven Tunic -0.0266
Vambrace -0.0271
Ex Machina -0.0274