The Special Series Straw Hats (One Piece) pack opened a +EV window at 10:03 AM PT on September 10 and peaked at +15.7% eleven minutes later, before closing back into negative territory at 10:16 AM PT. The whole window lasted 13 minutes.
What moved the needle
The grail tier is where the story starts. At open, the pool held a Roronoa Zoro (2024 One Piece) Grail at 0.03% odds, contributing $1.41 to EV on a $4,702 card. That card was still in the pool at peak and at close, so no grail was pulled during the window. But compare the Grail tier between before_window and at_open: before the window, the two grails were a Monkey D. Luffy (2025 One Piece) at $6,487 and a Tony Tony Chopper (2024 One Piece) at $5,548, each at 0.0267% odds. By 10:03 AM those two were gone, replaced by the Zoro (2024) at $4,702 and a Sanji (2025 One Piece) at $1,377 and a Monkey D. Luffy (2022) at $1,377, all at 0.03% odds. That's a significant reshuffling of the grail tier between the pre-window baseline and open.
The bigger driver of the window itself, the move from +6% at open to +15.7% at peak, was in the Lineup tier. Between 10:03 and 10:14, a cluster of higher-value Lineup cards entered the pool. A Roronoa Zoro (2025 One Piece) worth $353 joined at the top of the Lineup tier (contributing $7.06), alongside a Nami (2023 One Piece) at $193, a Jinbe (2023 One Piece) at $142, two additional O-Nami (2025) entries at $128 each, a Brook (2025) at $87, and a Sanji & Pudding (2025) at $87. Several lower-value Lineup cards from the open snapshot, including two Roronoa Zoro (2026 One Piece) entries at $89 each, a Sanji (2022 One Piece) at $125, a Sanji (2022 One Piece JPN) at $110, a Sanji (2025 One Piece CHI) at $110, and an O-Nami (2024 One Piece JPN) at $68, were no longer in the pool at peak. The net swap added roughly $8 to $9 in EV contribution across those Lineup positions.
Pool size stayed fixed at 53 cards across early readings, so the EV shift came from card composition changes, not from volume draining.
The window in brief: +EV for 13 minutes, peak of +15.7% at 10:14 AM PT, driven primarily by Lineup card turnover adding value mid-session, with the grail tier providing the floor that kept EV elevated throughout.