Within this site there are often references to various fields in the ratings which have underscores.
For example, we often hear of Cls Underscore, but what does that mean?
Quite simply, a Cls Underscore is the highest rated Cls value amongst the horses within that race and where the value is greater than zero. So anything underscored is simply the horse with the best rating of this field within the race.
Note that the positin within the ratings ranking (top rated horse is always shown first) doesn't determine the underscores. A horse which is rated the poorest in the race may still have one field, or more, with an underscore. So, for example, a horse may have the best jockey on board but it may still, effectively, only have three legs.
Similar to the Underscores are the Ranked Fields.