Got a Zekrom you've been scraping XL for, and it didn't come out 100%? Before you power up — 30 seconds. We simulated the entire Master top 100 to see whether that spread is fine to build.
For Zekrom, attack 15 is effectively mandatory, and the compromise line is about 15/15/14. Below is the result of running the Master top 100 through a battle simulator, plus the mirror, the same-stat rival, and best buddy. (Hundo 1-shield record: 48W 52L.)
Compromise IVs
15/15/14
At L50, at or above this the win/loss matchups match a hundo.
Build it or not — at a glance
✅
Just build · 15/15/14 or better
Win/loss matchups are effectively identical to a hundo. Just power it up.
⚠️
Conditional · around 15/15/13
You start dropping Giratina (Altered) (Shadow) and similar. If you rarely face them (low real pick rate), it's fine to run.
❌
Don't build yet · Attack 14 or below
Zekrom always loses CMP priority to the mirror and Reshiram at attack 14. Don't build it — wait for a better one.
🔬 Full-meta sim — all 100, who you meet & beat
1-on-1 battles vs the Master League top 100, per shield. Green = win, red = loss. (Rating 500 = even; higher = more comfortable.)
48W48%52L
339
540
488
409
318
500
344
845
214
436
206
581
500
478
232
369
257
565
554
500
500
433
483
508
877
363
801
619
562
635
312
260
801
589
369
663
231
736
312
297
486
521
459
470
866
285
826
268
505
393
302
260
529
410
352
845
337
608
725
468
573
505
113
519
581
597
502
226
226
479
801
641
458
733
339
456
736
671
390
625
543
866
638
845
241
417
766
665
826
804
218
429
692
295
736
413
616
586
252
611
⭐ Best Buddy (L51) effect — newly won matchups
Opponents you newly beat once best-buddied. The result depends on whether the opponent is best-buddied too, so both cases are shown.
Opp not BB (L50) · +5W
⭐
⭐
⭐
⭐
⭐
Opp also BB (L51) · +1W
⭐
※ The mirror and same-stat rival (Reshiram) return to a tie when the opponent is best-buddied too (both L51). So Best Buddy only wins the mirror when the opponent isn't best-buddied.
Why attack 15 is mandatory — CMP
Attack decides priority. Attack 14 always loses to a same-stat rival.
vsMirror (Zekrom vs Zekrom)
Mine (atk 14) vs Foe (atk 15)
shields0
L
301
shields1
L
467
shields2
L
467
vsvs rival · Reshiram
Mine (atk 14) vs Foe (atk 15)
shields0
W
782
shields1
Tie
500
shields2
L
467
Verdict by IV spread (Master League sim)
💡 15/15/15 at the top is the perfect IV (best); rows go to lower IVs downward.
Perfect·Battle-equal= win/loss identical to a hundo (no disadvantage — just use it).
Fine= it only loses to weaker (non-top) opponents, so it's acceptable to run.
N lost= it starts losing to N strong top-10 opponents — a real disadvantage.
CMP loss= at attack 14 you always lose the mirror / same-stat rivals.
‘Matchups lost’ = opponents you newly lose to at that spread (0/1/2 shields = how many shields are used).
Master League has no CP cap, so everyone is max level. When same-species (mirror) or same-stat Pokémon fire a charged move on the same turn, the higher effective attack goes first (CMP). An attack-14 Zekrom loses that priority to an attack-15 opponent. In the sim, the attack-14 mirror came out 0-shield=loss, 1-shield=loss, 2-shield=loss. In a mirror-heavy meta, attack 15 is effectively mandatory.
Where win/loss starts to split
Down to 15/15/14, win/loss matches a hundo. Below that, at 15/15/13, you begin losing Giratina (Altered) (Shadow) — that's the breakpoint line.
Best Buddy — depends on whether the opponent is too
Best Buddy (level +1) depends on whether the opponent is best-buddied. Against a non-best-buddied opponent (L50) you newly win 5 matchups at 1 shield; against a best-buddied one (L51), 1. Top Master legendaries are usually best-buddied, so the mirror and same-stat rivals go back to a tie when both are L51. It never hurts, but it doesn't magically win the mirror.
Note that this line moves with the meta. If usage shifts or a new Pokémon arrives, the breakpoints move and a spread that's fine today can get shaky. This analysis is for Season 28 (2026.09.08~12.01); when the season changes we re-run the full top-100 sim and update it.
⭐Best Buddy (L51) effectBB CP 4620 · L51
Best-buddying even a compromise improves every matchup and beats same-stat rivals.
Hundo record by shield count
shields 0
62W · 38L
shields 1
48W · 52L
shields 2
50W · 50L
Bottom line — attack 15 is non-negotiable (mirror CMP), compromise line 15/15/14. Based on the Season 28 (2026.09.08~12.01) meta; updated when the season changes.
FAQ
Q. Do I need a hundo Zekrom?
No. Down to 15/15/14, win/loss matchups are effectively identical to a hundo. At or above that, just power it up.
Q. Attack is 14 — can I just build it?
Not recommended. At attack 14 you lose CMP priority to the mirror and same-stat rivals — a fight that should be 50:50 becomes 0:100.
Q. How long does this hold?
It's the Season 28 (2026.09.08~12.01) meta. When the meta shifts, the breakpoints and the compromise line move, so we re-run the full top-100 sim each season and update it.
Method
BasisSeason 28 (2026.09.08~12.01)ScopeMaster League Top 100Shields0 · 1 · 2Level50 / Best Buddy 51Battle engineGBL Note Simulator (PvPoke-based)Baseline15/15/15Last calculated2026-10-09
✔ Calculated & analyzed by GBL Note
These verdicts come from simulating each spread against the entire Master League top-100 across 0/1/2-shield scenarios with the open-source PvPoke engine. If no matchup flips versus a hundo it's 'Perfect/Battle-equal'; if it only loses to weaker (non-top) opponents it's 'Fine'; once it loses to a top-10 opponent it's 'N lost' by the number of losses. Attack 14 loses mirror priority — 'CMP loss'.
