- Win Rate
- 44.7%
- Pick Rate
- 0.7%
- Ban Rate
- 0.7%
Cassiopeia vs Jax
- Patch
- 26.19
- Games
- 664
- Lane
- All Lanes
- Tier
- All Tiers
- Last Updated
- Oct 5, 2026 UTC
- Methodology
- Data Methodology
- Author
- Dakota Chinnick
Cassiopeia vs Jax is a decisive matchup in LoL patch 26.19. Jax wins with a 66.7% win rate (+33.3%) over Cassiopeia based on 6 games. Jax wins the early laning phase while Cassiopeia scales better into the late game. Below you'll find the best Cassiopeia build, runes, laning stats, and strategies for the Cassiopeia vs Jax matchup.
Cassiopeia Matchup Breakdown
Use the dropdown to select an opponent and see a detailed breakdown of how Cassiopeia performs against them. You'll get head-to-head win rates, laning stats, the best build and runes for the matchup, and early vs late game analysis — all based on real ranked data.
Who wins Cassiopeia vs Jax?
Cassiopeia wins 66.7% of these games. With this many games the true rate is most likely between 35.4% and 87.9% (95% range).
- Expected
- 48.5% From both champions' overall Top win rates
- Matchup effect
- +18.2 pts Observed minus expected
- Sample
- 9 games Lane: Top
- vs patch 26.18
- — Not enough games on both patches
Lane: Top · Ranked Solo/Duo & Flex · North America server · All ranks · Patch 26.19 · Sep 24 – Sep 28
Key takeaways
- Only 9 Cassiopeia vs Jax games were recorded in the Top role on patch 26.19 — too few to say who is favored. Treat the numbers below as provisional.
How we calculate this
Games: ranked Solo/Duo and Flex games on the North America server from the patch shown. Remakes (games under 5 minutes) are excluded.
A game only counts when Cassiopeia and Jax played the same position on opposite teams, so roaming, lane swaps within a team or a champion merely being in the same game never count as this matchup.
The 95% range is a Wilson score interval. Confidence comes from how wide that range is: within ±3 points is very high, ±5 high, ±8 moderate, anything wider low. Below 20 games a matchup is not classified at all.
Expected win rate combines both champions’ win rates in this lane (same games and filters) with the log5 formula: E = A(1−B) / (A(1−B) + B(1−A)). Matchup effect = observed − expected.
"What changes" compares Cassiopeia's choices in this matchup with the same champion's other games in the same lane, and lists a change only when it is at least 3 points and statistically significant (two-proportion z-test, |z| ≥ 2, 20+ games).
Results are not split by rank: the sample per rank is too small for honest per-rank matchup numbers.
Cassiopeia vs Jax Laning Stats
Only 9 games have a 15-minute snapshot so far — the lane-phase numbers appear from 30.
Whole-game averages
Cassiopeia vs Jax Win Rate by Game Length
Cassiopeia's win rate against Jax by game length. The dot is the win rate, the bar its 95% range and the dashed line the champion's usual win rate at that length. Lengths with fewer than 25 games are left blank.
No game length stands out: Cassiopeia's results against Jax in short and long games are within the margin of error of each other.
Cassiopeia vs Jax Power Spikes
Who is ahead at each stage, measured from these games. A stage reads "Even" when the difference is inside the margin of error, and "Insufficient data" when there are too few games to tell.
- Lane (15 min)Insufficient data
- First itemInsufficient data
- Games under 20 minInsufficient data
- 20–30 min gamesInsufficient data
- 30+ min gamesInsufficient data
What Cassiopeia Changes Against Jax
Only 9 games so far — too few to compare what Cassiopeia players do in this matchup with their usual choices (needs 20).
Best Cassiopeia Build vs Jax
Usual Cassiopeia build (Top)
55.0% win rate · 20 games
Against Jax
Not enough matchup-specific build data: only 0 of 9 Cassiopeia games against Jax carried a complete build, which is too few to recommend an item path from. Use Cassiopeia's standard build instead.
Builds are ranked by the lower edge of their win rate range, not the raw win rate, so a build seen in a handful of wins never outranks a proven one.
Best Cassiopeia Runes vs Jax
Usual Cassiopeia runes (Top)
Conqueror
50.0% win rate · 68 games
Against Jax
Too few games for a matchup-specific rune page yet — use the usual page.
Plan your Cassiopeia draft in Draft Lab
Draft Lab lays out both teams lane by lane with live matchup win rates, damage profiles and game-phase lean, and suggests picks and bans from current meta data.
- Full 5v5 draft board
- Lane matchup win rates
- Pick and ban suggestions
Cassiopeia matchup data for League of Legends patch 26.19. The table below shows Cassiopeia's win rate, gold difference, and performance stats against every champion in the current meta. Click any champion name to see a detailed head-to-head breakdown including the best Cassiopeia build, runes, laning stats, and early vs late game analysis for that specific matchup.
Help us maintain accuracy! If you notice incorrect stats, missing data, or any issues, your feedback directly improves the quality of our data for the entire community.
Cassiopeia vs Jax FAQ - Patch 26.19
Who wins Cassiopeia vs Jax?
Only 9 Cassiopeia vs Jax games were recorded in the Top role on patch 26.19 — too few to say who is favored. Treat the numbers below as provisional.
What is Cassiopeia's win rate against Jax?
Cassiopeia wins 66.7% of 9 Top games against Jax on patch 26.19 (95% range 35.4–87.9%). Based on both champions' overall Top win rates, 48.5% would be expected.
Does Cassiopeia counter Jax?
There are only 9 Cassiopeia vs Jax games in this lane on patch 26.19 — too few to answer reliably yet.
Who wins lane, Cassiopeia or Jax?
There are not enough games with a 15-minute snapshot yet (9) to say who wins lane.
Does Cassiopeia outscale Jax?
There are too few games of each length to tell yet.
When is Jax strongest against Cassiopeia?
On current data there is no stage of the game where Jax is ahead of Cassiopeia beyond the margin of error.
What should Cassiopeia build against Jax?
There are not enough games for a matchup-specific core, so use Cassiopeia's usual Top core: Rod of Ages, Liandry's Torment, Rylai's Crystal Scepter.
What runes should Cassiopeia use against Jax?
Use Cassiopeia's usual Conqueror page (Precision + Sorcery); there are too few games for a matchup-specific page.