Soft Bubble Strategy: How to Survive & Thrive with Any Stack Size

Dominate? Survive? Is it time to gamble?

As you approach the money in poker tournaments, the best approach will depend on multiple factors, not just how much you need the cash.

Concepts like ICM and chipEV get tossed around by poker’s intelligentsia, yet even the most studious can be clueless.

Stack asymmetry, field sizes, player pools, payout structures, varying formats, table configurations, and future game considerations all come into play when making money decisions. Figuring out what matters most — and when — is tough business.

This is the first in a series of MTT articles where I’ll guide you through navigating the money bubble and the crucial stages leading up to it.

What is the Soft Bubble?

Unlike the stone bubble, where one more elimination guarantees payouts — the soft bubble is considerably more elastic, harder to pin down. We know when it ends, but when does it begin?

It marks the stage where the possibility of making the money starts influencing strategy, though less drastically than the stone bubble.

Since ICM applies risk premiums (RP) from the start of a tournament, zealots argue for adjustments from hand 1. But treating it as gospel can backfire — playing too tight too early while others ignore it often means only punishing yourself.

I earmark the soft bubble’s emergence when around 10% of the remaining field needs to bust before making the money. For example, in a 200-runner field with 25 players paid, I would start adjusting with 45 players remaining.

In the example for this article, we are looking at a 1,000-runner tournament with 125 paid and 225 remaining players or 100 eliminations from the money. To some, this might feel early to begin making adjustments, but it’s not as crazy as it seems.

Bubble Factors & The Big Stack

Adjusting your Raise-First-In (RFI) strategy 100 eliminations from the money can seem a bit far-fetched. However, in the ICM model, significant risk premiums are already coming into play due to the bubble factors.

Bubble factors for a 1000-runner tournament with 225 remaining and 125 paid, 28bb average. These translate into risk premiums which affect preflop and postflop strategies. In ICM, losing chips hurts more than gaining them helps. So even when the Under-The-Gun (UTG) player is chipleading their table, they’re not free to go bananas.

Let’s look at the UTG player’s RFI strategy in ChipEV and compare it to HRC’s ICM-adjusted strategy:

Holdem Resources Calculator (HRC) RFI strategy for UTG playing a 50bb stack in an asymmetric configuration (meaning there is a wide variety of stack sizes at the table) with an average of 28bb average. UTG opens 18%.

25bb effective UTG RFI strategy in chipEV from Lucid Poker Trainer. UTG opens 18%.

Notice that in both solutions, the UTG player’s RFI remains 18%. The bubble factors aren’t yet strong enough for the early-position table captain to bulldoze the table. However, there is a noticeable change in the shape of the range.

In the Lucid chipEV output, UTG opens the suited 9x8x, Tx8x, and Jx9x at full frequency. But in the HRC solution, these become pure folds, losing $ev if they open. Similarly, in chipEV, 5x5x is a pure open but sees a significant frequency reduction in the ICM model. The chipEV mixes like suited 8x7x, 7x6x, Qx8x and Kx7x are losing $ev in the ICM model as opens. In a vacuum, removing these would result in a lower RFI %, so what changes?

In the HRC output, you’ll see that Ax9x offsuit starts opening at over half weight compared to chipEV, where it never opens. Offsuit combos like KxTx and QxJx, along with suited Ax2x, increase their raising frequency, making marginal $ev.

As the money bubble looms, preflop blocking effects come into play affecting the edges of your opening range.

Remember, this is the big stack in the earliest position. You could reasonably assume the later position you are in, the more of a releasing effect is experienced. We’ll explore whether that holds true in a future article.

The key takeaway: having the most chips doesn’t necessarily mean playing more hands—at least, not yet.

But what about the other stacks?

Mid-Stacks

In this table configuration, there are three mid-stacks:

• Under the Gun+1 (UTG1) or EP: 33bbs
• High-Jack (HJ): 25bbs
• Button (BTN) or BU: 29bbs

Let’s dive into two of them and look for observable patterns. Once again, we’ll compare the Lucid chipEV solutions with the HRC output.

The Early Position Mid-stack

HRC’s RFI strategy for UTG1, playing a 33bb stack in an asymmetric configuration (28bb average), has them opening 18.9% of hands.

In chipEV simulations from Lucid Poker, UTG1 opens 21% of hands when playing with a 25bb effective stack.

Here, we start to see some noticeable differences.

1. Drop in RFI %: In Lucid, UTG1 opens 21%. In HRC, that number drops to 18.9%. — a 2% reduction due to bubble factors.
2. Range Construction: Similar to the UTG output, HRC removes many of the chipEV fringe combos. Mixed-frequency chipEV opens like small suited connectors, the middling suited one and two gappers, weak suited kings, offsuit broadway, and 4x4x all become pure folds in the ICM model. As before, offsuit Ax hands increase in frequency. In HRC, Ax9x offsuit becomes a pure open compared to 56% frequency in chipEV. However, it is not completely the same as Ax2x suited, seeing a reduction in frequency compared to the UTG output.

When looking at outputs, determining the rationale for them can be murky. Is UTG1 tightening up strictly because of the bubble factors? Or is it the bubble factors accentuated by the positional disadvantage and stacks behind? How relevant is the Cutoff’s (CO) short stack when opening? While we can’t name with perfect accuracy at all times what the computer is doing, looking at other scenarios can help us identify more accurately the solution’s rationale.

Let’s look at the late position Mid-Stacks strategy.

The Late Position Mid-Stack

HRC’s RFI strategy for BTN, playing a 29bb stack in an asymmetric configuration (28bb average), has them opening 41.4% of hands.

In chipEV simulations from Lucid Poker Trainer, the BTN opens 45% of hands with a 25bb effective stack.

Comparing these two charts for the BTN, notice a recurring pattern with the previous charts (UTG and UTG1 chipEV vs. HRC outputs):

• Drop in RFI%: It is telling that the position that can VPIP the most profitably, the BTN, loses 10% of its opening range. In chipEV, BTN opens 45%; under ICM adjusted range, that drops to 41.4%. Once again, the folds come from the fringe of the range: the weakest suited combos, the bottom offsuit opens, even 3x3x lower their frequency.

However, a distinguishing factor here is that BTN’s range construction remains the same. It already opens all the combos with blocking effects like Ax and Kx combos. This means there is no other way to expand profitably. Here, there is no expected value (EV) gained by swapping combos, and only EV is saved by folding the weakest parts of our range.

The fact that a playable BTN stack chooses to offload 10% of its opens 100 away from the money speaks to the ICM model’s appraisal of playing for chips. Chips lost are worth more than chips won.

Playing the Mighty Short-Stack

In this HRC setup, we have one short stack with 11bbs playing in the CO.

Let’s see how the ICM models differ from chipEV when you are the short stack.

HRC’s RFI strategy for the CO with an 11bb stack in an asymmetric configuration (28bb average) shows a VPIP of 31.6%.

• Red: Min-open
• Purple: Open shove (All-in)

In chipEV simulations from Lucid Poker, the CO shoves its entire 31% range with a 10bb stack.

There are marked differences between these two charts and the others we’ve compared:

• No Drop in RFI%: In both models, the CO plays approximately 31% of hands. The bubble factors do not significantly impact frequency. Being short-stacked affords the CO a resilient RFI since their bubble factors are low, making their strategy play closer to chipEV.
• Range Splitting: A major difference between CO’s strategy and the others (except the Small Blind [SB]) is the inclusion of open shoves (23.3% of their range). Unlike in chipEV, where the solver prefers pure open-shoving, the ICM model introduces both min-opens and shoves, a hallmark of ICM-adjusted strategies.

Short-Stack Range Splitting – Open Shoves

Under ICM, the short stack benefits from splitting their range, jamming a capped selection that includes strong hands such as pocket pairs up to TxTx, offsuit Ax like AxKx, and suited KxQx. The inclusion of these strong combos allows the CO to incorporate hands that can’t profitably min-open but still perform decently in all-in situations, such as QxTx offsuit and Tx8x suited.

From HRC: The CO’s range split and the players to act responses. When facing CO’s all-in, BTN will continue as a call or reshove for a total 11.3%. When it folds to Small Blind, they will call or reshove for a total 16.7%. When it folds to the Big Blind, they will call 21.9%.

The above action breakdown for this HRC output shows us how tight the players left to act can call or reshove after the CO open shoves. Below are the chipEV responses to Cutoff’s open shove at 10 big blinds effective:

Lucid Poker BTN response to CO open shove at 10 big blinds effective in chipEV. Button calls 16%.

Lucid Poker trainer SB response to CO open shove at 10 big blinds effective in chipEV. Small Blind calls 21%.

Lucid Poker trainer BB response to CO open shove at 10 big blinds effective in chipEV. Big Blind calls 26%.

Comparing the HRC output to the chipEV solutions shows us that in every case, the player calling in the ICM model does so significantly tighter:

• BTN: In chipEV, the BTN calls 16% but in ICM continues 11.3%.
• SB: In chipEV, calls 21% but in ICM continues 16.7%.
• BB: In chipEV, calls 26% but in ICM calls 21.9%.

Even though the players to act have low bubble factors versus the CO, they still experience a dramatic decrease in calls when compared to chipEV. This is due to CO’s range splitting. Since CO is jamming 23% and not 31%, the players behind need to reconstruct their ranges to play versus a tighter open-shove range, resulting in their steep % decrease compared to chipEV.

Short-Stack Range Splitting – Min Opens

With the remaining 8.3% of their range, the CO adopts a polarized min-opening strategy, balancing their strongest hands (JxJx through AxAx) against Ax and Kx combos that are content to fold when shoved on.

This approach is highly effective for a short stack, as the big blind—the most likely caller—faces a tough dilemma:

1. Flatting against a polar range risks an equity realization or domination problem postflop.
2. Reshoving carries the risk of running into the CO’s premium hands.

In either case, the CO benefits—either stealing the blinds without risking their stack or doubling up when called and winning.

Key Takeaways from the Emerging Soft Bubble

In this article, we’ve taken a high-level look at strategy adjustments as the soft bubble begins to emerge. Here are some key insights:

• Risk premiums exist from the start of a tournament and increase as the money nears.
• Big stack aggression isn’t automatic, it depends on bubble factors and the big stack’s position relative to the table.
• Ranges contract for all but the short stack, either by removing combos or swapping for better blockers.
• This far from the money, short stacks benefit from lower bubble factors, translating to unaffected raising frequencies. This means you can play reasonably close to chipEV, albeit with a split-range strategy.

Next time, we’ll look at how things change as we get closer to the bubble.

If you’d like to learn more about aggressive tournament play, read: This Greedy Value Bet Strategy Will Help You Win More Tournaments

See you at the tables.