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
Heatran
FireSteel
OFFENSIVE CHECK
View matchup
66.479
92.8%
Standard error 4.40 points
▾
252+ SpA Heatran Magma Storm vs. 252 HP / 252+ SpD Ferrothorn: 468-552 (132.9 - 156.8%) -- guaranteed OHKO
02
Charizard-Mega-X
FireDragon
OFFENSIVE CHECK
View matchup
23.104
91.8%
Standard error 5.70 points
▾
252+ Atk Tough Claws Charizard-Mega-X Flare Blitz vs. 252 HP / 0 Def Ferrothorn: 888-1048 (252.2 - 297.7%) -- guaranteed OHKO
03
Talonflame
FireFlying
OFFENSIVE CHECK
View matchup
23.151
77.3%
Standard error 8.70 points
▾
252+ Atk Choice Band Talonflame Flare Blitz vs. 252 HP / 0 Def Ferrothorn: 744-880 (211.3 - 250%) -- guaranteed OHKO
04
Zapdos
ElectricFlying
OFFENSIVE CHECK
View matchup
88.403
66.1%
Standard error 7.11 points
▾
252+ SpA Zapdos Heat Wave vs. 252 HP / 252+ SpD Ferrothorn: 288-340 (81.8 - 96.5%) -- guaranteed 2HKO after Leftovers recovery
05
Volcanion
FireWater
DEFENSIVE CHECK
View matchup
20.201
71.9%
Standard error 10.00 points
▾
252+ Atk Ferrothorn Power Whip vs. 252 HP / 252+ Def Volcanion: 109-130 (29.9 - 35.7%) -- 36% chance to 3HKO
06
Lopunny-Mega
NormalFighting
OFFENSIVE CHECK
View matchup
23.653
68.3%
Standard error 9.56 points
▾
252+ Atk Lopunny-Mega High Jump Kick vs. 252 HP / 0 Def Ferrothorn: 384-452 (109 - 128.4%) -- guaranteed OHKO
07
Tornadus-Therian
Flying
OFFENSIVE CHECK
View matchup
25.728
61.1%
Standard error 9.61 points
▾
252+ Atk Tornadus-Therian Superpower vs. 252 HP / 0 Def Ferrothorn: 190-224 (53.9 - 63.6%) -- guaranteed 2HKO after Leftovers recovery
08
Ferrothorn
GrassSteel
SOFT CHECK
View matchup
56.782
48.7%
Standard error 6.63 points
▾
252+ Atk Ferrothorn Knock Off (97.5 BP) vs. 252 HP / 0 Def Ferrothorn: 74-88 (21 - 25%) -- 0.1% chance to 4HKO
09
Garchomp
DragonGround
OFFENSIVE CHECK
View matchup
46.425
61.0%
Standard error 10.03 points
▾
0- SpA Garchomp Fire Blast vs. 252 HP / 252+ SpD Ferrothorn: 156-184 (44.3 - 52.2%) -- guaranteed 3HKO after Leftovers recovery
10
Clefable
Fairy
SOFT CHECK
View matchup
103.091
54.1%
Standard error 8.30 points
▾
252+ SpA Clefable Flamethrower vs. 252 HP / 252+ SpD Ferrothorn: 224-268 (63.6 - 76.1%) -- guaranteed 2HKO after Leftovers recovery
11
Metagross-Mega
SteelPsychic
DEFENSIVE CHECK
View matchup
26.499
59.1%
Standard error 9.55 points
▾
252+ Atk Ferrothorn Knock Off vs. 252 HP / 252+ Def Metagross-Mega: 68-82 (18.6 - 22.5%) -- possible 5HKO
12
Keldeo
WaterFighting
OFFENSIVE CHECK
View matchup
27.996
57.5%
Standard error 9.34 points
▾
252+ SpA Choice Specs Keldeo Focus Blast vs. 252 HP / 252+ SpD Ferrothorn: 416-492 (118.1 - 139.7%) -- guaranteed OHKO
13
Bisharp
DarkSteel
OFFENSIVE CHECK
View matchup
28.501
56.9%
Standard error 9.28 points
▾
252+ Atk Bisharp Low Kick (100 BP) vs. 252 HP / 0 Def Ferrothorn: 184-218 (52.2 - 61.9%) -- 97.7% chance to 2HKO after Leftovers recovery
14
Skarmory
SteelFlying
SOFT CHECK
View matchup
28.353
54.0%
Standard error 9.36 points
▾
252+ Atk Skarmory Brave Bird vs. 252 HP / 0 Def Ferrothorn: 124-147 (35.2 - 41.7%) -- 80.8% chance to 3HKO after Leftovers recovery
15
Excadrill
GroundSteel
SOFT CHECK
View matchup
152.309
38.0%
Standard error 6.66 points
▾
252+ Atk Excadrill Earthquake vs. 252 HP / 0 Def Ferrothorn: 147-174 (41.7 - 49.4%) -- guaranteed 3HKO after Leftovers recovery
16
Scizor-Mega
BugSteel
SOFT CHECK
View matchup
25.659
48.4%
Standard error 9.87 points
▾
252+ Atk Scizor-Mega Superpower vs. 252 HP / 0 Def Ferrothorn: 254-300 (72.1 - 85.2%) -- guaranteed 2HKO after Leftovers recovery
17
Landorus-Therian
GroundFlying
SOFT CHECK
View matchup
32.197
40.8%
Standard error 8.66 points
▾
252+ Atk Landorus-Therian Earthquake vs. 252 HP / 0 Def Ferrothorn: 154-183 (43.7 - 51.9%) -- guaranteed 3HKO after Leftovers recovery
18
Serperior
Grass
SOFT CHECK
View matchup
26.72
34.3%
Standard error 9.18 points
▾
252+ SpA Serperior Hidden Power Fire vs. 252 HP / 252+ SpD Ferrothorn: 132-156 (37.5 - 44.3%) -- guaranteed 3HKO after Leftovers recovery
19
Rotom-Wash
ElectricWater
SOFT CHECK
View matchup
27.886
22.1%
Standard error 7.86 points
▾
252+ SpA Rotom-Wash Hidden Power Fire vs. 252 HP / 252+ SpD Ferrothorn: 160-192 (45.4 - 54.5%) -- 5.1% chance to 2HKO after Leftovers recovery
Ranked #6 with 19.00% usage. Sorted by conservative score.