Methodology

Should I Rip? tracks Arena Club's slab-pack pools in real time and surfaces the underlying expected-value math so buyers can make informed decisions. We check each pack's published pool every 15 minutes (1 minute for hot packs), compute per-pack EV, and store the history in Postgres. Every page reflects the most recent snapshot.

We don't tell you whether to rip. We report the data — EV, pool shape, pull odds, recent crossings, Collect Safe nets — and let you make the call.

How EV is computed

Each pack has a pool of cards. The published pool gives us each card's hit rate (the probability of pulling that specific card); we estimate each card's value ourselves — a best-effort read on what the market would actually pay, drawn from recent sold results across public marketplaces, with rank-based interpolation where no direct comp exists. Expected value:

EV = Σ (card_value × hit_rate)

If EV exceeds pack price, the pack is +EV. The percentage difference is the EV % shown across the site. By design, AC sets packs to be slightly −EV most of the time. But pools change continuously — cards get pulled, grails get added, inventory burns. The +EV moments are when the math briefly flips.

What "crossed +EV" means

A pack crosses +EV when its computed EV ticks from below pack price to above. We log every crossing as a discrete event. These events are usually short-lived: the +EV pack tends to get bought out within minutes to hours, which drops it back below zero. The home page tracks the count and timing of these events; the alerts list will fire when they happen.

Pool composition shape

For each pack we histogram the card pool by V/P — value as a multiple of pack price — across 16 log-spaced buckets. Red bars are below break-even (a single pull of this card loses money on this pack). Green bars are above. The shape tells you what kind of pack it is: a left-heavy red shape is a slow grind; mass on the right end is a top-heavy lottery; a green-dominant shape is +EV.

Collect Safe (Arena Club's addon)

Collect Safe is AC's optional buyback. Rules (per AC, as of 2026):

• Cost: 10% added to pack price (always).
• Buyback floor: AC will repurchase the pulled card for the greater of (80% of pack price) or (90% of card AC value).

Whether Collect Safe is worth it depends on pool composition, and on a single rip it's pure variance — so we don't hand you a verdict. The CS Trigger column shows the one number that lets you decide: the share of pulls on which Collect Safe's floor actually activates (a card worth less than ~0.889× the pack price, where the 80%-of-pack floor beats just selling it). On the pack page we also show the full math — the expected Collect Safe payout from the live pool, compared to (a) selling on the AC marketplace (which charges 10%) and (b) selling privately at recovery rates of 70/80/85/90% of AC value depending on liquidity. It's a fact about AC's product, not a verdict on the pack.

Caveats

• Slab Packs are entertainment products. Past EV doesn't predict future pulls.
• Our value estimates are best-effort reads on what the market would pay, not guaranteed sale prices — and how confident we are varies by card. A liquid slab that sells many times a day in the same grade has tight, reliable comps; a 1/1 grail or a thin, off-set card may have no direct sold result at all, so we lean on comparable cards and rank-based interpolation. Treat those as rougher.
• Pools shift. Pull a grail and EV drops; AC seeds a supergrail and EV jumps. Numbers shown are point-in-time.
• Liquidity matters. A high-EV pack with rare, illiquid cards may net less than a lower-EV pack with deep marketplace demand.
• Should I Rip? is independent. We are not affiliated with Arena Club, and we earn no commission on anything you buy there — outbound links are provided purely for your convenience.

Feedback & corrections

Spot an error in the methodology, or have a suggestion? Send it straight to us — no account needed. We read everything.