---
title: "Once in a Mewllion case on Cases.gg: odds, RTP & drops"
description: "Once in a Mewllion ($153.87) on Cases.gg, a CS2 case site: advertised RTP 89.50% from 18 items with odds, observed 203.73% over 461 openings in 30 days."
url: https://gambatracker.com/cases/cases-gg/once-in-a-mewllion
rendered: 2026-11-12T14:21Z
---

[Case sites](https://gambatracker.com/case-sites) / [Cases.gg](https://gambatracker.com/case-sites/cases-gg) / [Once in a Mewllion](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion)

# [Cases.gg](https://gambatracker.com/case-sites/cases-gg) · Once in a Mewllion

A box on Cases.gg (classic), first seen 2 Nov 2026. Every value is Cases.gg's own item price.

[24h](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=24h) [7d](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=7d) [30d](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion) [All](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=all)

Price · $153.87

Advertised RTP · 89.50% · EV $137.71 from 18 items

Observed RTP, 30d · 203.73% · 461 openings, odds method

Variance · 63.1× · of price², per opening

Tail share · 1 in 133 · of openings carry half the EV

Below price · 97.7% · of openings return less than the price

## Advertised vs observed · per window, 95% band and the advertised marker

observed, 95% band advertised outside band small sample

24 hours · 12 openings · below min

7 days · 349 openings · below min

30 days · 461 openings · below min

since tracking started · 461 openings · below min

-0.5% 227.3% 455.0%

**Small sample.** 461 openings and 3.5 expected rare hits: below the 100 openings and 5 hits the test needs, so no verdict.

## Windows · the test per window

| Window | Openings | Observed | Dev. | Method |
| --- | --- | --- | --- | --- |
| [24h](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=24h) | 12 | 5.21% ±449.4 | — | odds |
| [7d](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=7d) | 349 | 188.16% ±83.3 | — | odds |
| [30d](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion) | 461 | 203.73% ±72.5 | — | odds |
| [All](https://gambatracker.com/cases/cases-gg/once-in-a-mewllion?window=all) | 461 | 203.73% ±72.5 | — | odds |

Enough sample: 100 openings and 5 expected rare hits (odds method) or 1,000 openings (sample method).

## Items and odds · 18 items · odds sum to 1 · observed counts over 461 openings, 30 days

Share of the expected value, most valuable first; colour is the item's rarity.

| Item | Odds | Value | EV share | Observed | Expected | Hot / cold |
| --- | --- | --- | --- | --- | --- | --- |
| [1999 Pokemon Base Set Shadowless 1st Edition Holo Mewtwo #10 PSA 10 GEM MINT other](https://gambatracker.com/items/1999-pokemon-base-set-shadowless-1st-edition-holo-mewtwo-10-psa-10-gem-mint) | 1 in 400 | $19.8K | 35.9% | 2 | 1.2 | 1.74× |
| [2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) | 1 in 200 | $9,900 | 35.9% | 9 | 2.3 | 3.90× |
| [2010 Pokemon Heartgold & Soulsilver Triumphant Holo Mew #97 PSA 10 GEM MINT other](https://gambatracker.com/items/2010-pokemon-heartgold-and-soulsilver-triumphant-holo-mew-97-psa-10-gem-mint) | 1 in 67 | $1,650 | 18.0% | 6 | 6.9 | 0.87× |
| [2023 Pokemon SV Black Star Promo 151 Ultra Premium Collection Mew ex #53 PSA 10 other](https://gambatracker.com/items/2023-pokemon-sv-black-star-promo-151-ultra-premium-collection-mew-ex-53-psa-10) | 1 in 27 | $140 | 3.8% | 16 | 17.3 | 0.93× |
| [Funko Pop! Games Pokemon Mewtwo (Flocked) SDCC Exclusive Figure #581 other](https://gambatracker.com/items/funko-pop-games-pokemon-mewtwo-flocked-sdcc-exclusive-figure-581) | 1 in 33 | $125 | 2.7% | 11 | 13.8 | 0.80× |
| [2020 Pokemon Battle Academy Mewtwo GX #31 PSA 10 GEM MINT other](https://gambatracker.com/items/2020-pokemon-battle-academy-mewtwo-gx-31-psa-10-gem-mint) | 1 in 25 | $77.00 | 2.2% | 19 | 18.4 | 1.03× |
| [Crown Zenith Booster other](https://gambatracker.com/items/crown-zenith-booster) | 1 in 17 | $4.20 | 0.2% | 30 | 27.7 | 1.08× |
| [Paldean Fates Booster other](https://gambatracker.com/items/paldean-fates-booster) | 1 in 17 | $3.50 | 0.2% | 27 | 27.7 | 0.98× |
| [Lost Origin Booster other](https://gambatracker.com/items/lost-origin-booster) | 1 in 17 | $3.45 | 0.2% | 22 | 27.7 | 0.80× |
| [Brilliant Stars Booster other](https://gambatracker.com/items/brilliant-stars-booster) | 1 in 13 | $3.39 | 0.2% | 38 | 34.6 | 1.10× |
| [Fusion Strike Booster other](https://gambatracker.com/items/fusion-strike-booster) | 1 in 13 | $3.25 | 0.2% | 38 | 34.6 | 1.10× |
| [Twilight Masquerade Booster other](https://gambatracker.com/items/twilight-masquerade-booster) | 1 in 13 | $2.25 | 0.1% | 29 | 34.6 | 0.84× |
| [Play! Pokémon Prize Pack Series Four Booster other](https://gambatracker.com/items/play-pokemon-prize-pack-series-four-booster) | 1 in 13 | $2.20 | 0.1% | 33 | 34.6 | 0.95× |
| [Shrouded Fable Booster other](https://gambatracker.com/items/shrouded-fable-booster) | 1 in 13 | $2.00 | 0.1% | 22 | 34.6 | 0.64× |
| [Clay Burst Booster other](https://gambatracker.com/items/clay-burst-booster) | 1 in 13 | $1.05 | 0.1% | 31 | 34.6 | 0.90× |
| [McDonald's Match Battle 2022 Booster other](https://gambatracker.com/items/mcdonalds-match-battle-2022-booster) | 1 in 13 | $0.90 | 0.1% | 31 | 36.9 | 0.84× |
| [Paldea Evolved Fun Pack (3 Cards) other](https://gambatracker.com/items/paldea-evolved-fun-pack-3-cards) | 1 in 13 | $0.60 | 0.0% | 51 | 36.9 | 1.38× |
| [Trick or Trade 2024 BOOster other](https://gambatracker.com/items/trick-or-trade-2024-booster) | 1 in 13 | $0.37 | 0.0% | 46 | 36.9 | 1.25× |

Values are Cases.gg's own item prices for physical goods; EV share = odds × value ÷ EV. Hot / cold compares observed drops of each item with odds × openings; small expected counts are left blank. Odds read from `cases-gg:api/cases/details`, 12 Nov, 09:09 UTC.

## Biggest drops · from this case, by value

[1999 Pokemon Base Set Shadowless 1st Edition Holo Mewtwo #10 PSA 10 GEM MINT other](https://gambatracker.com/items/1999-pokemon-base-set-shadowless-1st-edition-holo-mewtwo-10-psa-10-gem-mint) Hidden $154 $19.8K 128.7x 2026-11-10 03:30 UTC

[1999 Pokemon Base Set Shadowless 1st Edition Holo Mewtwo #10 PSA 10 GEM MINT other](https://gambatracker.com/items/1999-pokemon-base-set-shadowless-1st-edition-holo-mewtwo-10-psa-10-gem-mint) Hidden $154 $19.8K 128.7x 2026-11-05 03:41 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-09 04:10 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-09 03:55 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-09 03:47 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-09 03:44 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-09 03:39 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) [Kick/PapaGambles $20k+ Rewards](https://gambatracker.com/players/cases-gg/Kick%2FPapaGambles%20%2420k%2B%20Rewards) $154 $9,900 64.34x 2026-11-08 20:01 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) Hidden $154 $9,900 64.34x 2026-11-06 02:35 UTC

[2002 Pokemon Expedition Holo Mew #19 PSA 10 GEM MINT other](https://gambatracker.com/items/2002-pokemon-expedition-holo-mew-19-psa-10-gem-mint) [Arrrbaccos](https://gambatracker.com/players/cases-gg/Arrrbaccos) $154 $9,900 64.34x 2026-11-05 13:29 UTC

## Latest drops · newest first

[All Latest drops →](https://gambatracker.com/drops?casino=cases-gg&case=once-in-a-mewllion)

[Lost Origin Booster other](https://gambatracker.com/items/lost-origin-booster) Hidden $154 $3.45 0.02x 2026-11-11 19:07 UTC

[Shrouded Fable Booster other](https://gambatracker.com/items/shrouded-fable-booster) Hidden $154 $2.00 0.01x 2026-11-11 19:07 UTC

[Paldea Evolved Fun Pack (3 Cards) other](https://gambatracker.com/items/paldea-evolved-fun-pack-3-cards) Hidden $154 $0.60 0.00x 2026-11-11 19:07 UTC

[Play! Pokémon Prize Pack Series Four Booster other](https://gambatracker.com/items/play-pokemon-prize-pack-series-four-booster) Hidden $154 $2.20 0.01x 2026-11-11 19:07 UTC

[2020 Pokemon Battle Academy Mewtwo GX #31 PSA 10 GEM MINT other](https://gambatracker.com/items/2020-pokemon-battle-academy-mewtwo-gx-31-psa-10-gem-mint) Hidden $154 $77.00 0.50x 2026-11-11 19:07 UTC

[Paldean Fates Booster other](https://gambatracker.com/items/paldean-fates-booster) [CODE: FREEMAN 400$ LB](https://gambatracker.com/players/cases-gg/CODE%3A%20FREEMAN%20400%24%20LB) $154 $3.50 0.02x 2026-11-11 19:07 UTC

[Paldea Evolved Fun Pack (3 Cards) other](https://gambatracker.com/items/paldea-evolved-fun-pack-3-cards) Hidden $154 $0.60 0.00x 2026-11-11 19:06 UTC

[Twilight Masquerade Booster other](https://gambatracker.com/items/twilight-masquerade-booster) Hidden $154 $2.25 0.01x 2026-11-11 19:06 UTC

[Trick or Trade 2024 BOOster other](https://gambatracker.com/items/trick-or-trade-2024-booster) Hidden $154 $0.37 0.00x 2026-11-11 19:06 UTC

[McDonald's Match Battle 2022 Booster other](https://gambatracker.com/items/mcdonalds-match-battle-2022-booster) Hidden $154 $0.90 0.01x 2026-11-11 19:06 UTC

## Catalog changes · price, advertised RTP and contents, per capture

| Captured | Price | Advertised | Items |
| --- | --- | --- | --- |
| 2 Nov, 21:39 UTC | $154 | 89.50% | 18 |

Each opening is tested against the capture in force when it happened; a price or odds change starts a new one.

listed other 100.0% best hit $19.8K (128.7x)

18+

**Case opening is gambling with skins as the currency.** At 89.5% RTP, every $100 put into cases returns $89.50 on average: an expected loss of $10.50 per $100, before any one lucky or unlucky opening. A big drop here says nothing about the next one.

[BeGambleAware](https://www.begambleaware.org/) [Help & limits](https://gambatracker.com/responsible-gambling)

How these figures are produced and labelled: https://gambatracker.com/llms.txt