Observed target KO or switch rate is upstream p: the fraction of relevant encounters where the target was knocked out or switched out. Standard error is upstream d. The conservative score is p − 4d. These ladder observations do not prove a set-specific counter.
How to read this table
Use encounter count and standard error to judge the sample. Damage estimates below use inferred sets and remain separate from the observed ladder metric.
#
Checker
Encounters
Conservative score
Target KO or switch rate
01
Tyranitar
RockDark
OFFENSIVE CHECK
View matchup
171.205
66.4%
Standard error 3.61 points
▾
252+ Atk Tyranitar Rock Slide vs. 252 HP / 0 Def Zapdos: 317-374 (82.5 - 97.3%) -- guaranteed 2HKO after sandstorm damage and Leftovers recovery
02
Blissey
Normal
DEFENSIVE CHECK
View matchup
172.341
65.8%
Standard error 3.61 points
▾
252+ SpA Zapdos Thunderbolt vs. 252 HP / 252+ SpD Blissey: 97-115 (13.5 - 16.1%)
03
Registeel
Steel
DEFENSIVE CHECK
View matchup
31.176
77.9%
Standard error 7.43 points
▾
252+ SpA Zapdos Thunderbolt vs. 252 HP / 252+ SpD Registeel: 90-106 (24.7 - 29.1%) -- possible 5HKO
04
Aerodactyl
RockFlying
OFFENSIVE CHECK
View matchup
50.319
70.2%
Standard error 6.45 points
▾
252+ Atk Choice Band Aerodactyl Rock Slide vs. 252 HP / 0 Def Zapdos: 399-470 (103.9 - 122.3%) -- guaranteed OHKO
05
Celebi
PsychicGrass
SOFT CHECK
View matchup
67.869
53.5%
Standard error 6.05 points
▾
252+ SpA Celebi Psychic vs. 252 HP / 252+ SpD Zapdos: 105-124 (27.3 - 32.2%) -- 55% chance to 4HKO after Leftovers recovery
06
Zapdos
ElectricFlying
SOFT CHECK
View matchup
58.692
46.6%
Standard error 6.51 points
▾
252+ SpA Zapdos Thunderbolt vs. 252 HP / 252+ SpD Zapdos: 127-150 (33 - 39%) -- 9.6% chance to 3HKO after Leftovers recovery
07
Metagross
SteelPsychic
SOFT CHECK
View matchup
63.793
34.6%
Standard error 5.96 points
▾
252+ Atk Metagross Explosion vs. 252 HP / 0 Def Zapdos: 702-827 (182.8 - 215.3%) -- guaranteed OHKO
08
Swampert
WaterGround
SOFT CHECK
View matchup
119.419
24.7%
Standard error 3.95 points
▾
252+ SpA Swampert Ice Beam vs. 252 HP / 252+ SpD Zapdos: 132-156 (34.3 - 40.6%) -- 49.8% chance to 3HKO after Leftovers recovery
09
Salamence
DragonFlying
SOFT CHECK
View matchup
72.543
27.9%
Standard error 5.26 points
▾
252+ Atk Salamence Rock Slide vs. 252 HP / 0 Def Zapdos: 212-250 (55.2 - 65.1%) -- guaranteed 2HKO after Leftovers recovery
10
Claydol
GroundPsychic
SOFT CHECK
View matchup
33.8
35.2%
Standard error 8.21 points
▾
252+ Atk Claydol Explosion vs. 252 HP / 0 Def Zapdos: 455-536 (118.4 - 139.5%) -- guaranteed OHKO
11
Skarmory
SteelFlying
SOFT CHECK
View matchup
133.584
11.7%
Standard error 2.78 points
▾
252+ Atk Skarmory Drill Peck vs. 252 HP / 0 Def Zapdos: 59-70 (15.3 - 18.2%) -- possible 8HKO
12
Suicune
Water
SOFT CHECK
View matchup
59.092
15.7%
Standard error 4.73 points
▾
252+ SpA Suicune Ice Beam vs. 252 HP / 252+ SpD Zapdos: 137-162 (35.6 - 42.1%) -- 89.1% chance to 3HKO after Leftovers recovery
13
Starmie
WaterPsychic
SOFT CHECK
View matchup
57.579
14.6%
Standard error 4.66 points
▾
252+ SpA Starmie Ice Beam vs. 252 HP / 252+ SpD Zapdos: 147-174 (38.2 - 45.3%) -- guaranteed 3HKO after Leftovers recovery
14
Gengar
GhostPoison
SOFT CHECK
View matchup
21.481
31.0%
Standard error 9.98 points
▾
0- Atk Gengar Explosion vs. 252 HP / 0 Def Zapdos: 259-305 (67.4 - 79.4%) -- guaranteed 2HKO after Leftovers recovery
15
Dugtrio
Ground
SOFT CHECK
View matchup
25.901
14.2%
Standard error 6.87 points
▾
252+ Atk Choice Band Dugtrio Rock Slide vs. 252 HP / 0 Def Zapdos: 224-264 (58.3 - 68.7%) -- guaranteed 2HKO after Leftovers recovery
16
Forretress
BugSteel
SOFT CHECK
View matchup
20.988
22.3%
Standard error 9.09 points
▾
252+ Atk Forretress Explosion vs. 252 HP / 0 Def Zapdos: 531-625 (138.2 - 162.7%) -- guaranteed OHKO
Ranked #7 with 25.36% usage. Sorted by conservative score.