Introduction
With just a glance, the Range Viewer lets you get a feel for what hole cards the server might be holding at any point in time. The server’s range is the union of all possible hole cards it could have, given the decisions it has made in the hand so far. This is illustrated by color-coding the traditional 13×13 grid that groups all possible hold’em starting hands.
The server’s range at the beginning of a hand (click to enlarge)
Since the server has not yet made any decisions, it could be holding any combination of hole cards, except those using either of the two hole cards in your own hand. The most likely holdings are in red, with descending probability becoming orange, then yellow, green, and finally no color if there is zero chance of having those hole cards.
You can hover your mouse cursor over any of the cells to see a breakdown by the exact cards. This way, you can see all 12 combos for offsuit hands, 6 combos for pairs, and 4 combos for suited hands. For example, ace-king suited, or AKs, has 4 different ways of getting dealt, one for each suit: AsKs, AhKh, AdKd, AcKc. That explains why suited hands are less likely at the start and are shown in yellow. Note in the picture that hands with a ten or two are slightly less likely. This is because the Range Viewer takes into account the cards known to you, like your hole cards (Ts2c) or the community cards.
The Range Viewer also displays your showdown equity against the server’s range. This is the fraction of the pot you would expect to win at showdown, on average, if you stopped the hand and dealt any remaining board cards.
Reviewing ranges from previous hands or decisions
When you are playing, the Range Viewer will default to showing you the “Current” range for the server in the present scenario. However, you can easily see ranges from earlier in the hand, or from previous hands that are now finished. To look at past hands, use the Review Previous Hands dropdown box in the upper-left corner of the main window. There you can select any of the last 100 hands played. Then you can use the Review Hand Actions slider in the upper-right corner of the main window to navigate to the point in the hand you would like to examine. Tip: you can usually use Shift + mousewheel to adjust the Review Hand Actions slider.
See how the server balances its ranges for each decision
Using the Range Viewer, you can visually see what ranges and actions the server considered for all of its decisions. As explained above, use the Review Hand Actions slider so that the game state is just before the server decision you want to examine. The Range Viewer will update to show you the server’s range at that precise point in the hand. Then, on the actual Range Viewer window, you can move the slider at the top to step through all the possible actions the server could have taken. The hand grid will update to show you the corresponding range it would have used for that action. Tip: you can usually use Ctrl + mousewheel to move this slider.
Prelude’s min-raise range on the button
Prelude’s call range vs 3bb button open
Note that at the bottom of the Range Viewer, a percentage is given that tells you how often the server will choose that decision. This is across its entire range and not for a particular hand.
See which hands the server will defend with against your bets
You can also use the Range Viewer to visually inspect how the server will react to several possible bet sizes. Normally when playing and it is your turn, you can simply adjust the slider at the top of the Range Viewer. Or, as explained above, you can use the Review Hand Actions slider so that the game state is just before you made a decision. The Range Viewer will update to show you the range that the server will “defend” or continue with against that bet size. Here, defend means to call or raise. Put another way, the hands it will not fold. In many cases, the server will use a mixed strategy, meaning it considers several possible replies with a particular hand, like usually folding but occasionally raising as a bluff.
Prelude’s defend range vs 2bb open
Notice that the exact probability the server will fold is given below the colored grid. This value is across its entire range and not for an individual hand.
Estimate the effectiveness of bluffs and value bets
When examining how the server will react against your bets, two other statistics are provided.
Pure Bluff EV represents your immediate fold equity. This is calculated with the assumption that if the server does not fold to your bet, then you will not invest any more chips into the pot and will automatically lose the hand. Put another way, it gives you the value of a bet if your only hope of winning the hand was causing the server to fold to that bet.
Semi Bluff EV is a rough estimate, similar to Pure Bluff EV, except with the assumption that the server calls your bet with its entire defend range and you both then check all the way to showdown. In reality, this is unlikely, and also ignores the chance you get raised, but it can still make for a helpful baseline. For example, you can always get the exact value of going allin at any point by moving the Range Viewer slider all the way to the right when it is your turn to act.
Raising allin will be an additional 334 chip loss from this point
To demonstrate the usefulness of these statistics, consider when you are last to act on the river and considering a bet. If you have a poor hand with a 0% chance to win at showdown, then any bet with a Pure Bluff EV that is positive will be an improvement over checking and giving up. If you have a strong hand, you can use Semi Bluff EV to get an estimate for the optimal value bet size.
Bluffing 1/3 pot is 114 chips better than checking
Caution: these statistics can be misinterpreted or misused easily. For example, positive values do not necessarily indicate a “profitable” play. Importantly, the values are relative to the current state of the hand, ignoring all the chips you have already invested, which could easily be more than any positive bluff value, making the net outcome of the hand negative. You also have to consider your current showdown equity, since the value of checking can be higher than any bet size. On top of that, remember these statistics are only for exploiting the specific strategy the server is using, and will not apply to any other opponent. You will have to use your own judgement.