Introduction
When training preflop with PLO Trainer, you'll notice that there are two tabs on the right hand side - one for your range (which shows every single hand in the range), and one for categories (which organizes different hands and groups them together based on certain characteristics).
With the range view, you can see every hand at a glance and use the filter below to search for a specific hand or group of hands. This is useful if you want to lookup your specific hand, but what if you want to see other similar hands or a certain type of hand? For example, we know that a lot of double suited hands are opening from EP, but exactly which ones? This is where the categories function comes in.
Categories - What do the Percentages Mean?
When you first open the categories tab, you'll notice a bunch of different hand classes (such as unpaired double-suited, unpaired single-suited, unpaired rainbow, etc.) listed under the Full Range column. The percentage beside these headers is the total number of hands in our full range that make up this category.
For example, unpaired double-suited hands make up 9.51% of our entire range and unpaired single-suited hands make up 51.75% of our entire range.
Beside these labels, we can see a red and blue bar to the right hand side. Blue means fold, and red means pot. Inside these bars, we can see another percentage - these percentages are how many hands inside that range are doing something.
For example, in the unpaired double-suited category 59% of hands are folding and 41% of hands are raising to full pot.
Simplifying the numbers a little bit, roughly 10% of the time we'll have a hand from this category preflop and roughly 40% of these hands want to open from EP.
Categories - Drilling Deeper
When you click on a master category (or use the dropdown arrow), you'll see the category is expanded and broken down further into sub-categories.
For example, if we click on the "Unpaired Double-Suited" category we see the following categories show up:
Unpaired Double-Suited is now broken into Ace-High, Connected, and Disconnected - along with the new percentages for each category. Remember, these percentages show how often we are doing something with all of our hands from this category, so our Unpaired Double-Suited Ace-High category is opening 77% of the time from EP.
You can drill down even further as long as you see an arrow to get a better understanding of each category.
Categories - Training
Beside each category (and sub-category) if you drill down further has a checkbox beside each category name. If you click the checkbox and then click the "T" shaped icon above, it'll load that category/filter for you to train and study.
The icon looks like this: 
Please note that the checkboxes only work on Desktop and are not optimized to show up on mobile or tablet yet. This feature will be available in the future.
Categories - Definitions
Unpaired Double-Suited (9.51% of entire range)
Hands in this category have no pair and are exactly double suited - meaning they can only contain exactly two suits (for example, two hearts and two clubs).
Unpaired Single-Suited (51.76% of entire range)
Hands in this category have no pair and have one suit. This can be single suited (two hearts, one club and one spade), triple suited (three hearts and one club) or monotone (4 cards of the same suit)
Unpaired Rainbow (6.34% of entire range)
Hands in this category have no pair and are not suited. They will always have one heart, one club, one spade, and one diamond.
One Pair Double-Suited (3.80% of entire range)
Hands in this category have one pair in hand and are exactly double suited - meaning they can only contain exactly two suits (for example, two hearts and two clubs).
One Pair Single-Suited (23.51% of entire range)
Hands in this category have one pair in hand and have one suit. This can be single suited (two hearts, one club and one spade), triple suited (three hearts and one club) or monotone (4 cards of the same suit)
One Pair Rainbow (4.04% of entire range)
Hands in this category have one pair in hand and are not suited. They will always have one heart, one club, one spade, and one diamond.
Two Pair Double-Suited (0.17% of entire range)
Hands in this category have two pairs in hand and are exactly double suited - meaning they can only contain exactly two suits (for example, two hearts and two clubs).
Two Pair Single-Suited (0.69% of entire range)
Hands in this category have two pairs in hand and have one suit. These hands will always have one suit with exactly two of a suit and two other rainbow cards (for example, two hearts, one club and one spade)
Two Pair Rainbow (0.17% of entire range)
Hands in this category have two pairs in hand and have no suit. These hands will never be suited and will always have one heart, one club, one spade, and one diamond.
When studying and training, it's important to focus on the categories that have the biggest impact on our winrate and the categories we see the most often. For example, we only see two pair (or double paired) hands about 1% of the time overall, but we are dealt an unpaired single-suited hand almost 52% (or half) of the time.