"Small ball" or "inside baseball" (metaphorically) refers to a strategy of putting forward claims that are too insignificant or too specialized, or demonstrating points in a way that is too plodding or mechanical, or arguing with over-fine interpretations of the evidence. It is the result of a few factors: being so immersed in a field, or example, that one loses perspective, the "big picture." Small ball can be very convincing to other specialists who also have no perspective, but is likely to bore those in other fields. We should, in fact, have fine, detailed knowledge at the granular level, but the danger is in losing sight of what anyone else cares about. Sometimes debates in other fields, not my own, seem trivial, because I am not acculturated into the lore of the field.
Sometimes, the perspective is so limited that more important matters are forgotten. I am very guilty of that myself. For example, I should have probably spent more time in Apocryphal Lorca explaining how Lorca's death reverberated in leftwing circles in the 1930s. To me it's such an obvious point that I forgot to give it its proper magnitude and was later zapped by a reviewer. Quite rightly.
It is interesting that "inside baseball" refers both to a strategy of playing the game, an offense based on squeeze plays, stolen bases, bunts, etc... rather than power hitting and slugging, and also to a way of talking about baseball, one that emphasizes the finer points of strategy that the casual fan does not care about. I only knew of the second meaning, but when I looked it up I saw that it was synonymous with "small ball." Granted, small ball can be a thing of beauty on the diamond, with its scrappy, opportunistic quality.