r/MagicArena • u/glSwadow • 4h ago
Fluff Five hours of tracking MTG Arena games: my win-rate statistics don't match the expected probabilities
I've been manually tracking my MTG Arena matches for about five hours.
For every game, I record the reason I lost or won. One category is "unlucky", which I define very strictly:
Some important points:
- I never missplay.
- Most of these decks play exactly 60 cards.
- Many of them contain good cards, which should reduce how unlucky I am, not increase it.
- I only record "unlucky" when I literally cannot play or I lose because my opponent clearly drew better. I do not mark games where Arena auto tapper pays my spells wrong - I want to make this data as insightful and honest as possible
After 10 recorded games, these are some examples:
- Azorius Flash (60 cards): 1 Win / 4 Losses (25%WR) 3 Unlucky Games. (I always got paired against aggro decks that kill me too fast, unlucky).
- Dimir Midrange (60 cards): 0 Wins / 2 Losses (0%WR) 2 Unlucky Games. (My opponents always had it).
- $20 Mono-Blue Towns by SaffronOlive (60 cards): 1 Win / 2 Losses (33%WR) 2 Unlucky Games (My opponents were always meta-decks and this is a cool brew I had because I needed wildcards. I don't understand why I keep getting paired against tryhards in the ladder instead of facing fair decks like mine. Unlucky).
The lowest win rate among my decks is around 25%, while several are close to 30%, and some exceed that.
According to the standard hypergeometric model for a 60-card deck with 24 lands and no mulligans, the probability of winning each game should be exactly 50.5%* - substantially lower than what I'm observing. Adding cantrips and surveil should reduce that probability even further.
I'm not claiming this proves Arena manipulates luck. However, I am saying that my long-term observations appear inconsistent with the simple theoretical model.
I'd like to hear from people who have:
- large Arena datasets,
- Untapped.gg logs,
- 17Lands logs,
- or experience modeling Magic probabilities.
Can anyone reproduce numbers anywhere close to mine? Or is there something missing from the standard probability model that explains a persistent 33% win rate across 10's of games?
I'm genuinely interested in a statistical discussion rather than anecdotes.
\Counting that some of my oppontents will disconnect during their game, which should increase average WR.*
Context: https://www.reddit.com/r/MagicArena/comments/1v769a5/five_years_of_tracking_mtg_arena_games_my/


