To Burst the Bubble

How Field Size Affects Decisions During Hand-for-Hand Play

I was back at it last weekend for the $2,200 buy-in PokerStars US Summer Series event at Philadelphia Live!

Like many modern tournaments, this event featured three Day Ones—Thursday, Friday, and Saturday—with the surviving field returning for Day Two on Sunday. Only those returning players would make the money.

In the wee hours late on Friday night, I had an interesting situation come up on the stone bubble. I’ll include as much relevant information as I can, so you can decide what you would’ve done in my spot.

1.) Twelve (12) players had advanced from Thursday.
2.) There were eighteen (18) players remaining from my start day, with 17 advancing, and we were playing hand-for-hand.
3.) Saturday was expected to be the biggest field. I was guessing 30-35 players would advance from Saturday.
4.) Average stack was about 380,000.
5.) Blinds were 4,000-8,000 with a big blind ante.
6.) The shortest stack was about 50,000—enough for two orbits—but that player was not at my table.
7.) The next shortest stack had 109,000.
8.) I was the third-shortest stack.
9.) Exact pay structure was unknown, but we assumed a typical min-cash of 1.5-1.8 times the buy-in.

Got all that? OK, here’s the hand.

It folds to the button—the second-shortest stack in the tournament, and a strong player—who shoves for 109k.
After anteing 8k, I have 175k including the 8k I’ve posted for the big blind.
The small blind folds.
What do I call with? Specifically, I’m interested in how far down I should go with my Ax offsuit. Think about this situation for a second and respond to the poll before reading on.

An important skill in poker is knowing what’s important. There are a million factors at play in spots like this—how can our brains figure out which ones take precedence in real time at the table? (This question is the focus of my book The Poker Brain, hint hint!)

In a spot like this, it’s crucial that I have the button covered by enough that even if I call and lose, I still have a reasonable chance of cashing. In that scenario, I would basically be fighting it out with the short stack at the other table for the final money spot. If the stack sizes were reversed, I’m pretty sure I couldn’t call here even with AKs. (Running a quick sim—yeah, it looks like only QQ or better can call in that spot!)

But since I do cover my opponent by a reasonable amount, I know I can at least consider calling with some good-but-not-premium hands. How far to take it, though?

The next factor to consider here is an underrated one by most tournament players. In case you haven’t guessed by the title of this post, that factor is field size.

With a borderline hand, would you rather call on the stone bubble with 27 players left, or 227? Again, if you don’t know this answer already, think about it a bit before reading on.

A good way to work through the above question is to ask, “what do I gain by calling and winning?” This framing helps clarify the problem a bit better than the negative perspective of, “in which case would bubbling feel worse?”

With 227 players left, the upside of calling and winning is that you still have to get through hundreds of players before you see meaningful pay jumps and reach the final table. With 27 players left, the upside of calling and winning is that you’ve already made the final three tables, and you’re in position to make a run at the final table quite soon.

Additionally, the upside of folding is greater in a very large field, where you’re likely to reach the money in just a couple of additional hands. In a short field, it’s reasonable to expect to remain on the bubble for a while. You could fold, and then still be battling on the bubble hours later.

Clearly then, you should be more inclined to take a risk on the bubble in a short field than in a big one. The effect is actually quite dramatic.

Running ICMizer for an 18-person bubble with a standardish pay structure, I’m supposed to call here with 66+, AT+, A9s, KQs.

Change it to a 180-person bubble, and suddenly the calling range tightens all the way up to TT+, AQ+, AJs.

My situation was somewhere between these two, although it’s impossible to say where exactly, since the ultimate number of players cashing was unknown.

Running the numbers for a 63-person bubble, my calling range is supposed to be 99+, AJ+. In practice, I think I can call a tiny bit looser than this, since we wouldn’t expect to reach the money as soon as we would in an actual 63-person field if I folded.

One key takeaway here is, regardless of the specifics, you simply can’t get very loose when you’re relatively short-stacked on the bubble. Any ace worse than AT is just asking for trouble in almost every scenario. If you never called off on the bubble with worse than AT when short-stacked, that strategy would likely serve you quite well.

In the actual hand, I had AJo, which felt right on the border to me in-game. Glad to see the computer overlords back me up! If the button had been a typical bubble short stack—which is to say, a nit—I would’ve folded fairly comfortably. As it was, I thought there were too many hands I was beating, and that I would have just enough chips left if I lost to justify calling. Still, I’m pretty sure I would’ve folded ATo.

The happy ending is that the button had ATo himself, and play finished for the night after I busted him.

I ended up finishing 40th in the tournament on Sunday, which is a story for another post.

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Good luck at the tables this week! Unless you’re against me in the online Bracelet events…