ACR Poker OSS XL Guide: Main Event Structures, Break-Even Fields and Second Mortgage Week

Three OSS XL Main Events touch the felt on Sunday, 20 September 2026, and one of them is sitting on a guarantee it may not cover. Here is the entry math on all three, the nosebleed week that follows, and what the last two editions actually paid.

Start with the smallest buy-in, because that is where the interesting number lives. ACR Poker's OSS XL schedule lists the $66 Main Event at $500,000 guaranteed, with Day 1A already played on 13 September and Day 1B, the final flight, on Sunday 20 September. ACR's own recap of the first flight put Day 1A at 2,401 entries, with 239 players bagging for the 27 September Day 2 and a player called Rastern001 leading on 11.78 million chips.

Now the arithmetic. ACR's $66 buy-in splits as $60 to the prize pool and $6 in fee; that is the same 10-to-1 pattern its published pools show elsewhere in the series, where a $630 High Roller with 1,175 entries built a $705,000 pool (1,175 × $600) and a $16.50 Splash with 4,584 entries built $68,760 (4,584 × $15). Apply it here: 2,401 × $60 = $144,060 banked from Day 1A. The guarantee is $500,000, so Day 1B has to find $355,940, which at $60 a head is 5,932.33, call it 5,933 entries. Day 1A drew 2,401. Unless the final flight pulls roughly two and a half times the first one, ACR is adding money, and re-entries in a $66 event on a Sunday with a dozen other tournaments running may not close a gap that size. If you play small buy-in Mains for value, this is the one on the calendar.

One caveat before anyone books a Sunday off work: ACR has not published the exact fee split for this event, so the $60 figure is inferred from the pattern above, and the Day 1B flight runs alongside $6.60 satellites that feed it directly. The structure is a six-hour flight on 12- and 10-minute levels with a 300,000 starting stack, late registration through level 30 and a restart at level 36, all per the schedule page. Play on each flight continues until 10 percent of the field remains, according to ACR's preview of the first flight. If you are weighing ACR against the rest of the US-facing market, our ACR Poker review covers the software, banking and field quality in detail; this piece is only about the next ten days.

Second Mortgage Week is a joke with a $25,500 punchline

The name is ACR's, not ours. From Monday 21 September to Monday 28 September, the top of the OSS XL schedule turns into ten Nosebleed Stakes tournaments, two a day across five playing days, with buy-ins from $5,200 to $25,500 in No-Limit Hold'em and Pot-Limit Omaha, six-max and eight-max. ACR laid out the full slate in its 9 September announcement, and a press release the following day confirmed the same dates and range. No guarantees have been published for the ten events, which is normal at this end of the lobby: the fields are small, the pools are whatever walks in.

Why a poker reader who will never fire $25,500 should care: this is the second time ACR has run a dedicated nosebleed block, and the first one set a house record. That was the Highest Five, 19 to 23 April 2026, and its $25,500 Phil's Puff & Bluff drew 53 entries for a $1,325,000 prize pool (53 × $25,000 = $1,325,000, so the fee there was $500 a seat). Card Player described the $25,500 as the largest buy-in tournament ACR had run to that point, and reported the win went to AlwaysWithNuts for $371,000 with Alex Foxen second for $265,000, and that Chris Moneymaker took down the $10,300 six-max from a 51-entry field for $170,850. Foxen is one of the most consistent high-roller tournament players of the last decade and an ACR Pro; Moneymaker is the 2003 WSOP Main Event champion whose win started the online boom, also now on ACR's roster. Both are named in ACR's material as expected starters this week, alongside Winning Poker Network CEO Phil Nagy, who plays his own site's events under the screen name Justsomefish72 and, per PokerStrategy's coverage, made two final tables on the opening Sunday for $88,800.

Moneymaker's pitch for the week, in ACR's announcement, was aimed at the rest of us rather than the people buying in: "The great thing about the Nosebleed Stakes events is that you get to watch top-level poker players compete every day." He also said he had won a Nosebleed Stakes event "last time around" and was "looking forward to doing it again," which is a fair summary of April. The watching part matters because of a tool covered further down: every completed OSS XL final table can be replayed with all hole cards face up, which turns a $25,500 eight-max into study material for anyone with a browser.

The $2,650 Main has a new guarantee and a thin margin

The two flagship Mains, $2,650 for $2.5 million guaranteed and $1,050 for $2 million guaranteed, both open Day 1A on Sunday 20 September at 11:05. The schedule page gives the hour without a timezone; ACR's lobby runs on US Eastern time, and Card Player listed the March 2026 flights at 11:05 a.m. ET, so treat that as the working assumption. Day 1B for both is Sunday 27 September, Day 2 is Monday 28 September, and the final tables play Tuesday 29 September, the last day of the series.

The $2.5 million number is new. In the March 2026 edition the $2,650 Main carried a $2 million guarantee, and a post-series release reported 994 entrants for a $2,485,000 pool, won by Alex "Rushgold" Wasierski for $480,796. The September 2024 edition, per Poker.org's results roundup, drew 962 entries for $2,405,000, won by vousconfus for $465,317. At $2,500 to the pool per entry, covering $2.5 million takes exactly 1,000 entries. March fell 6 short of that mark; September 2024 fell 38 short. In both editions we checked, the field would not have covered the number ACR is now guaranteeing, so the site has raised the bar to a height its own recent history barely clears. Good for players, if the entries land where they did before: a $15,000 or $95,000 top-up is modest against a $2.5 million pool, but it is real.

The $1,050 is the opposite story: 2,000 entries covers $2 million at $1,000 a head, and the last two editions came in at 2,298 and 2,171. It is the safer guarantee and the softer field, in the sense that a four-figure buy-in on a US-facing network pulls in a lot of satellite winners and Sunday regs shot-taking off a good month. Note that in March the $1,050 champion took home less than the $2,650 champion despite a similar-sized pool, which tells you the $1,050 payout was flatter across a field more than twice as large; 2,298 entries against 994.

Those structure figures come from the schedule page and apply to both the $2,650 and the $1,050. Eight hours of late registration is a long window, and it means the Day 1A field is not fixed until the flight is nearly done, so anyone reading entry counts mid-afternoon on Sunday should wait for the bagging number before drawing conclusions about overlay. If you would rather not fire the full buy-in, ACR's schedule page says The Beast promotion is paying out $1,050 and $2,650 OSS XL tickets throughout September, and direct satellites into the $66 start at $6.60.

Everything else running on 20 September

The Mains are not the only reason the lobby will be busy. ACR's Sunday preview, matched by Card Player's report, has the $630 Sunday High Roller (OSS XL #215) at $750,000 guaranteed, a step up from the $600,000 it carried on the two previous Sundays, when it drew 1,118 entries for $670,800 on 6 September and 1,175 entries for $705,000 on 13 September. At $600 to the pool, $750,000 needs 1,250 entries, which is above both of those fields. Second overlay watch of the day, then, and a bigger buy-in for it.

Beneath that: OSS XL #216 at $215 for $250,000, a second $630 High Roller (#213H) for $250,000, the $2,650 Mini Phil's Thrill (#219) for $250,000 and its PLO twin (#220) for $200,000, an $88 PKO for $150,000, the $27.50 Sunday Smash for $100,000, the $16.50 Sunday Splash for $75,000, and mystery bounties at $109, $44 and $6.60. For anyone with a small roll, the Splash is worth a note: on 13 September it drew 4,584 entries, which at $15 a head is $68,760, so ACR topped it up by $6,240 to reach the $75,000 guarantee. Micro-stakes Sunday fields on this network are enormous, and even they can leave money on the table.

The leaderboard and the replayer

Two side pieces round out the series. The OSS XL leaderboard splits players into three bands by buy-in: High for $104.50 and up, Medium for $16.50 to $88, Low for anything under $15. First place pays $15,000, $7,500 and $4,000 respectively, out of a pool ACR puts at more than $60,000 in cash and tickets, and only in-the-money finishes score points. For a volume grinder who is going to play the schedule anyway, the Medium band is the quiet value: the $7,500 top prize is attached to buy-ins where the fields are large but the regs are not all grinding for leaderboard points.

The replayer is the more interesting addition. Every completed OSS XL final table is available through ACR's free replayer with all hole cards exposed, hand by hand, with no download and no account, per PokerStrategy's write-up linked above and ACR's own Sunday preview. It launched during this series, so the library is growing by the day, and once Second Mortgage Week starts it will hold eight-max final tables at $10,300, $15,400 and $25,500 with the cards face up. There is not much else in online poker that hands you a nosebleed final table, fully exposed, for free, and it is worth bookmarking before the week begins.

Sources: ACR Poker OSS XL schedule; ACR Poker, 14 September 2026 recap; ACR Poker, 11 September 2026 preview; ACR Poker, 9 September 2026 Second Mortgage Week announcement; ACR Poker, 18 September 2026 Sunday preview; ACR Poker, 7 September 2026 opening recap; PR Newswire, 10 September 2026; PR Newswire, 27 March 2026; Card Player, 19 September 2026; Card Player, 22 April 2026; Card Player, 20 March 2026; Poker.org, 1 October 2024; PokerStrategy, 13 September 2026.

18+. Poker involves risk; play with money you can afford to lose and take a break if it stops being fun.