04 May 2024 Many people misplay their strategies on monotone boards, either by c-betting too much or by raising too frequently. While monotone boards may appear infrequently, the probability of encountering one on the flop is 5.2%. This occurs roughly 1 per 20 flops, so if you don't know how to play them correctly, you could lose a significant amount of EV. What is a Monotone Board? Monotone boards consist of cards of the same suit only. Monotone boards can significantly affect the dynamics of the game. It makes the board very wet. While having top pair on a board like A♠Q♥7♣ is strong, having top pair on a monotone board like A♥Q♥7♥ is not, as it shifts the nuts from sets to flushes. Playing Monotone Boards In general, on monotone boards, the optimal checking frequency decreases to around 50%, and bet sizing should also be smaller. Next, let's discuss c-betting and donk-betting situations separately. C-betting on Monotone Boards The frequency of c-betting decreases on monotone boards because both ranges include many flushes, and there's less range advantage and nut advantage. Let's compare the situations on monotone boards and dry boards. Example #1 (Monotone board): Flop 9♥7♥4♥, UTG open-raises 2.5bb, BB calls. On this monotone board, UTG checks 34.9% and c-bets 65.1% of the time. You can also notice that small bet sizes become more preferable, and overbets are rarely used. If you delve deeper into the range, you will notice that the solver c-bets with every hand at certain frequencies. Betting exclusively with flushes would significantly narrow down the villain's range, making our play too straightforward. Therefore, it is essential to c-bet with an appropriate frequency using almost all types of hands, primarily focusing on high hearts, such as A♥ and K♥. Moreover, sets are also c-bet at a significant frequency. Looking at the overall range composition, UTG is ahead with 53% equity, but there is no a big difference in best hands (75%+ equity) and good hands (50-75% equity). The c-bet frequency changes based on how much better the overall range is. So let's compare it with dry boards. Example #2 (Dry board): Flop A♠Q♥7♣, UTG open-raises 2.5bb, BB calls. On this dry board, UTG checks 8.9% of the time and c-bets 91.1% of the time. Comparing this with the monotone board where UTG checks 34.9% and c-bets 65.1%, we do see the difference — a much higher c-bet frequency. Furthermore, it's worth noting the larger bet sizes compared to the monotone board — 73% of the pot bet at 28.6% of the time, and 127% (overbet) at 5.5% of the time. Overbet frequencies increase with strong sets like QQ or 77, top pair with top kicker, and weak pocket pairs. The solver prefers small bets with AA as even if it makes an overbet, there are few hands that will call it. Looking at the overall range composition, there's a significant advantage across the entire range compared to before. Equity is 63%, with many more strong hands, indicating that the opponent has a high proportion of trash hands (hands with 33% equity or less). Based on the above, on a monotone board, due to the lower overall range advantage and nut advantage, the frequency of c-bets decreases, and smaller sizes are more preferable. Donk Betting On monotone boards, there's a range of about 10% of hands that can be donked. As I mentioned earlier, on monotone boards, the overall range's advantage is lower. Furthermore, donk betting frequency increases in situations where the board favors the caller, such as flops with possible straights (like 4-5-6 or 2-4-5). On monotone boards the frequency of donk betting increases as the board gets lower. The 3-4-5 flop is an excellent spot for donk betting, and it's possible to donk bet around 26.7% of the time with a small size. Conclusion Monotone boards are special boards where a flush can potentially be completed with just one card. However, with a 5.2% probability of appearing on the flop, it's not a rare flop. Developing your strategy on monotone boards, don't forget to reduce the bet frequency of the entire range and make them smaller.
