Ron is a master of Wizard Chess. He has inherited his grandfathers old wizarding chess set. Unlike other hand me downs we get a sense that Ron is actually fond of this particular possession. We can imagine that he has some fond memories of him and his grandfather playing with these very same pieces. He feels connected to his grandfather through the love of this game and particularly this set.
We see that he beats Harry on a regular basis with this set and even the omniscient Hermione Granger. This begs the question why is Ron so good at chess which is a game of strategy and deep reflection, and yet kinda bad at everything else?
It can be argued that Harry and Hermione are not from the wizarding world and so they do not have a firm grasp of the game and so Ron is able to soundly beat them. However, that argument is refuted by Ron's brilliant and self-sacrificing game while they were trying to prevent Voldemort from getting theSorcerer's Stone. In my opinion Ron can be good at anything that he puts his mind to but he lacks self confidence.
As noted previously, Ron is always overshadowed by his brothers. There is nothing that Ron can do that will be spectacular since it has already been done by his brothers. This knowledge alone can put a damper on the ego. If Ron represents one end of the spectrum, there is no way to do something original since it had already been done before so just be your goofy self and hope for the best, Percy represents the other end, do whatever it takes to be the best and in the process become an ego maniac. Ron does not want to be like Percy. So he seeks out something that the other brothers and sister is not keen at. Something that is frivolous enough that wont catch their attention and he, Ron can for once be the only one good at it! And that something in Wizarding Chess. Unfortunately for him, his secret was outed when Dumbledore awards Griffyndor points for his amazing and spectacular game. Poor Ron!