Heads-Up Poker: A Strategic Guide to Winning One-on-One

24 Aug 2024

Heads-up poker differs significantly from the strategies used in a 6-max table. To become strong in heads-up pla you need to study specifically for it.

But many players don’t prepare intentionally for heads-up. So if you know how to play heads-up in more detail, you can gain a big advantage over the field.

In this article, we'll explore how to effectively approach heads-up situations.

What is Heads-Up?

If you're reading this article you probably already know what a Heads-Up (HU) is, but just to be sure, let's review what it is.

This can happen at a 6-max table where four players fold, or in scenarios where the game starts with just two players. 

For this article, we define heads-up as a game starting with only two players at the table.

Heads-Up Rules

Before diving into strategy, let’s quickly review the rules.

The cards are dealt starting with the Big Blind (BB) and ending with the SB. This may confuse some, as in other formats, the SB is dealt first. The action begins with the BTN (SB).

Heads-Up Strategy

To effectively play heads-up, focus on these three key aspects:

• Play aggressively
• Consider wide ranges
• Exploit your opponent’s tendencies

Play Aggressively

Heads-up play is far more aggressive compared to 6-max and full-ring formats. Players accustomed to 6-max might be surprised by the level of aggression involved in HU.

In heads-up, the SB and BTN are the same. Normally the SB is out of position (OOP), but in heads-up, the SB is in position (IP), so he can try to steal blinds with a very wide range.

This chart is the SB's opening range at 2.5bb (5% rake, 0.3bb CAP). It shows that you can open almost all cards except T4o-, 74o-, J3o-, 43o-, Q2o, 32o. In particular, you can open all suited cards.

This chart shows how the BB should defend against the SB's 2.5bb open. You can defend 63.6% of the time. Out of those, 6.5% should be with a 3-bet.

It's surprising to see that the 3-betting range includes Q8o, 93s and T4s.

The SB's defense against this BB 3bet (SB: 2.5bb open, BB: 10bb 3-bet) is also wide.

QTo should 4-bet 33% of the time, and J4s — 62.6% of the time.

Consider Wide Ranges

Given that the BB defends against the SB’s open 63.6% of the time, the ranges post-flop are extremely wide.

Let’s look at an example:
You're in the SB with Q♣9♠ and open for 2.5bb, and the BB calls.

The flop comes 8♠6♥4♦︎.

BB checks, SB?

In such a situation, both players’ ranges are wide, leading to a variety of possible actions. The flexibility of options is reflected in the complexity of range charts.

Exploit Opponents

Unlike 6-max tables, where you may not often face the same opponent, heads-up play involves continuous confrontation with the same player.  Also, as mentioned earlier, in heads-up, you play with a wide ranges, so you can quickly identify and exploit your opponent's tendencies.

For example, 6-max players who aren't familiar with heads-up may have narrower 3-bet or 4-bet ranges. If you see a 3-bet or 4-bet from such an opponent, you can be sure they have a stronger range than what a solver suggests.

In this way, by adopting a more exploitative strategy in heads-up poker, you can increase your win rate.

Heads-Up Flop Strategy

For this guide, we will focus on heads-up strategies for 100bb cash games with SRP, using GTO Wizard for assistance. The stack sizes or formats might be different (like MTT or Spin&Go), but the methods introduced here will be very helpful for analyzing other formats.

In practice, opponents often deviate from GTO. It is important to make the most profit from these deviations. The strategies introduced here will help you find these deviations.

First, check the overall frequencies. While these frequencies alone might not be very useful, but it will give you an idea of ​​whether it's above or below average.

As a general rule:

The ranges for BTN (SB) and BB are as follows:

You can get these pre-flop ranges for free in GTO Wizard. If you're interested, you can sign up to check them out.

Special Boards

Monotone and paired boards are treated as special boards. On these board textures, large sizes are rarely used.

On monotone boards, the check frequency is 61.8%, the 33% of the pot bet — 21.3%, and the 67% of the pot — 15.2%. Since there is often no nut advantage and equity is close on these flops, overbet is a rare option. Even with small bet sizes, the betting frequency decreases.

On paired boards, the check frequency is 32.9%, the 33% bet — 60.2%, and the 67% bet — 6.2%. Even though there is no nut advantage, there is a significant equity advantage.

Boards with a Straight

On straight boards (like 754 or QT8) overbets are rarely used. However, unlike the two board types mentioned above, 100% and 66% bets become more often.

On straight boards, the check frequency is 52%, the 33% bet is 16.1%, the 67% bet is 19.8%, the 100% size is 9.2%, and the 150% size is 3%. Overall, the 150% size is used quite often. However, many of these cases are on high card flops (like AJT or KQT) where overbets are frequently used.

When excluding A-high and K-high flops, the check frequency is 51.1%, the 33% bet is 17.5%, the 67% bet is 23%, the 100% size is 7.5%, and the 150% size is 1%.

A-High Boards

A-high boards are divided into six types:

• A-H-H (Ace-High-High)
• A-H-M (Ace-High-Mid)
• A-H-L (Ace-High-Low)
• A-M-M (etc.)
• A-M-L
• A-L-L

In this article, 'H' means A to T, 'M' means 9 to 6, and 'L' means 5 to 2. For example, a flop like AK4 is categorized as A-H-L.

When analyzing A-high boards, we will exclude monotone and paired boards from the special boards mentioned earlier.

1. A-H-H

For A-H-H boards, use large sizes like 100% or 150% of the pot. The opponent (BB) 3-bets many of the hands that connect well with these flops pre-flop, making them less likely to hit. SB (BTN) will have both nut and equity advantages.

For example, on a flop like A♥Q♥T♦︎, value bets are based on top pair, second pair plus straight draws. and we bet not only on heart flush draws, but also on diamond flush draws and many straight draws when we have a J or K.

This is a rare board with a large size and a 40% bet.

2. A-H-M

Use 150% or 33% sizes. The important factor here is whether it is easy to make a draw. In particular, if it is easy to make an OESD, the frequency of 150% size increases.

Let's compare two A-H-M boards: one where it's easy to create a draw and one where it's difficult.

In the chart, dark red represents overbets and light red — small bets (33% of the pot). The difference is clear.

Let's look at the equity distribution and equity percentage for each:

On the harder draw board A♥J♦︎6♣, the SB has more equity and overall higher equity distribution. This board tends to have high-frequency small bets.

3. A-H-L

Use a lot of small sizes. In actual games, there is not much EV loss even if you only choose small sizes, so it is a perfectly usable strategy. However, if you want to use a strategy with a slightly higher EV, it is better to use 150% size when 'H' becomes K or Q.

4. A-M-M

All sizes are mixed, but since it varies greatly depending on the board, it is difficult to remember a simple strategy for A-M-M.

For example, compare A♥9♦︎8♣ and A♥7♥6♦︎:

Both of these cards have no flush draws and are easy to make an OESD with two consecutive cards, but their strategies are very different. This is largely related to whether you have a set or two pairs.

Going back to preflop, the BB 3-bets all 88 and 99, and about 50% of 66, making A98r less likely to be a set on. Also, all A9s, A8s and 66% of A9o are 3-bet, making two pair less likely.

In other words, in A98r, it becomes difficult for the BB to make a nutted hand, so we can see that the BTN (SB) is overbetting more.

5. A-M-L

I think there is no problem with using only the 33% pot size. The larger size is used when 'M' is 9 or 8 (the difference between A9 and A8) and when the board is easy to make a straight draw.

6. A-L-L

Typically only small sizes are used.

Final Thoughts

To learn heads-up, it is important to use a special tools such as GTO Wizard. 

If you try it without experience, you might struggle. However, with practice, it can become a game where you can earn a lot. Additionally, heads-up skills are also useful in 6-max games, so why not use this opportunity to study them?